diff --git a/cmd/controller/controllers/volume_state_controller.go b/cmd/controller/controllers/volume_state_controller.go
index 4c72f465..28d79d0b 100644
--- a/cmd/controller/controllers/volume_state_controller.go
+++ b/cmd/controller/controllers/volume_state_controller.go
@@ -65,11 +65,15 @@ func (c *VolumeStateController) fetchInitialStorageState(ctx context.Context, vo
 			return nil
 		}
 
-		instanceIDs := make([]string, len(nodes))
+		instanceIDs := make([]string, 0, len(nodes))
 		instanceIDToNodeName := make(map[string]string, len(nodes))
-		for i, node := range nodes {
+		for _, node := range nodes {
 			instanceID := extractInstanceIDFromProviderID(node.Spec.ProviderID)
-			instanceIDs[i] = instanceID
+			if instanceID == "" {
+				c.log.WithField("provider_id", node.Spec.ProviderID).Warn("could not extract instance id from provider id")
+				continue
+			}
+			instanceIDs = append(instanceIDs, instanceID)
 			instanceIDToNodeName[instanceID] = node.Name
 		}
 
@@ -114,11 +118,15 @@ func (c *VolumeStateController) runRefreshLoop(ctx context.Context, volumeIndex
 				continue
 			}
 
-			instanceIDs := make([]string, len(nodes))
+			instanceIDs := make([]string, 0, len(nodes))
 			instanceIDToNodeName := make(map[string]string, len(nodes))
-			for i, node := range nodes {
+			for _, node := range nodes {
 				instanceID := extractInstanceIDFromProviderID(node.Spec.ProviderID)
-				instanceIDs[i] = instanceID
+				if instanceID == "" {
+					c.log.WithField("provider_id", node.Spec.ProviderID).Warn("could not extract instance id from provider id")
+					continue
+				}
+				instanceIDs = append(instanceIDs, instanceID)
 				instanceIDToNodeName[instanceID] = node.Name
 			}
 
@@ -162,10 +170,10 @@ func extractInstanceIDFromProviderID(providerID string) string {
 	}
 
 	// GCP format: gce://project-id/zone/instance-name
-	if strings.HasPrefix(providerID, "gce://") {
-		parts := strings.Split(providerID, "/")
-		if len(parts) >= 4 {
-			return parts[len(parts)-1]
+	if instanceID, ok := strings.CutPrefix(providerID, "gce://"); ok {
+		parts := strings.Split(instanceID, "/")
+		if len(parts) == 3 {
+			return instanceID
 		}
 	}
 
diff --git a/cmd/controller/controllers/volume_state_controller_test.go b/cmd/controller/controllers/volume_state_controller_test.go
index c048650b..11fdf01b 100644
--- a/cmd/controller/controllers/volume_state_controller_test.go
+++ b/cmd/controller/controllers/volume_state_controller_test.go
@@ -87,7 +87,12 @@ func TestExtractInstanceIDFromProviderID(t *testing.T) {
 		{
 			name:       "GCP format",
 			providerID: "gce://my-project/us-central1-a/instance-name",
-			want:       "instance-name",
+			want:       "my-project/us-central1-a/instance-name",
+		},
+		{
+			name:       "GCP format with missing zone",
+			providerID: "gce://my-project/instance-name",
+			want:       "",
 		},
 		{
 			name:       "Azure format",
diff --git a/pkg/cloudprovider/aws/provider.go b/pkg/cloudprovider/aws/provider.go
index 6db7fdd2..da5fb8ff 100644
--- a/pkg/cloudprovider/aws/provider.go
+++ b/pkg/cloudprovider/aws/provider.go
@@ -17,10 +17,6 @@ type Provider struct {
 	// AWS clients
 	ec2Client *ec2.Client
 
-	// Cached storage state
-	storageStateMu sync.RWMutex
-	storageState   *types.StorageState
-
 	// Cached network state
 	networkStateMu sync.RWMutex
 	networkState   *types.NetworkState
diff --git a/pkg/cloudprovider/aws/storage_state.go b/pkg/cloudprovider/aws/storage_state.go
index d017d8dd..d0629c25 100644
--- a/pkg/cloudprovider/aws/storage_state.go
+++ b/pkg/cloudprovider/aws/storage_state.go
@@ -15,9 +15,8 @@ func (p *Provider) GetStorageState(ctx context.Context, instanceIds ...string) (
 	p.log.Debug("refreshing storage state")
 
 	state := &types.StorageState{
-		Domain:          "amazonaws.com",
-		Provider:        types.TypeAWS,
-		InstanceVolumes: make(map[string][]types.Volume),
+		Domain:   "amazonaws.com",
+		Provider: types.TypeAWS,
 	}
 
 	instanceVolumes, err := p.fetchInstanceVolumes(ctx, instanceIds...)
@@ -26,11 +25,7 @@ func (p *Provider) GetStorageState(ctx context.Context, instanceIds ...string) (
 	}
 	state.InstanceVolumes = instanceVolumes
 
-	p.storageStateMu.Lock()
-	defer p.storageStateMu.Unlock()
-	p.storageState = state
-
-	return p.storageState, nil
+	return state, nil
 }
 
 // fetchInstanceVolumes retrieves instance volumes from https://docs.aws.amazon.com/AWSEC2/latest/APIReference/API_Volume.html
diff --git a/pkg/cloudprovider/gcp/provider.go b/pkg/cloudprovider/gcp/provider.go
index 01e93157..2d304026 100644
--- a/pkg/cloudprovider/gcp/provider.go
+++ b/pkg/cloudprovider/gcp/provider.go
@@ -2,6 +2,7 @@ package gcp
 
 import (
 	"context"
+	"errors"
 	"fmt"
 	"sync"
 
@@ -17,6 +18,7 @@ type Provider struct {
 	// GCP clients
 	networksClient    *compute.NetworksClient
 	subnetworksClient *compute.SubnetworksClient
+	disksClient       *compute.DisksClient
 
 	// Cached network state
 	networkStateMu sync.RWMutex
@@ -43,11 +45,17 @@ func NewProvider(ctx context.Context, cfg types.ProviderConfig) (types.Provider,
 		return nil, fmt.Errorf("creating subnetworks client: %w", err)
 	}
 
+	disksClient, err := compute.NewDisksRESTClient(ctx, clientOptions...)
+	if err != nil {
+		return nil, fmt.Errorf("creating disks client: %w", err)
+	}
+
 	p := &Provider{
 		log:               log,
 		cfg:               cfg,
 		networksClient:    networksClient,
 		subnetworksClient: subnetworksClient,
+		disksClient:       disksClient,
 	}
 
 	log.With("project", cfg.GCPProjectID).Info("gcp provider initialized")
@@ -71,10 +79,14 @@ func (p *Provider) Close() error {
 			errs = append(errs, fmt.Errorf("closing subnetworks client: %w", err))
 		}
 	}
+	if p.disksClient != nil {
+		if err := p.disksClient.Close(); err != nil {
+			errs = append(errs, fmt.Errorf("closing disks client: %w", err))
+		}
+	}
 
 	if len(errs) > 0 {
-		return fmt.Errorf("errors closing GCP provider: %v", errs)
+		return fmt.Errorf("errors closing GCP provider: %w", errors.Join(errs...))
 	}
-
 	return nil
 }
diff --git a/pkg/cloudprovider/gcp/storage_state.go b/pkg/cloudprovider/gcp/storage_state.go
index 83cbba2b..0ed4d70d 100644
--- a/pkg/cloudprovider/gcp/storage_state.go
+++ b/pkg/cloudprovider/gcp/storage_state.go
@@ -2,11 +2,140 @@ package gcp
 
 import (
 	"context"
+	"errors"
 	"fmt"
+	"math"
+	"path"
+	"strings"
+
+	"cloud.google.com/go/compute/apiv1/computepb"
+	"github.com/samber/lo"
+	"google.golang.org/api/iterator"
 
 	"github.com/castai/kvisor/pkg/cloudprovider/types"
 )
 
 func (p *Provider) GetStorageState(ctx context.Context, instanceIds ...string) (*types.StorageState, error) {
-	return nil, fmt.Errorf("GetStorageState not yet implemented for GCP")
+	p.log.Debug("refreshing storage state")
+
+	state := &types.StorageState{
+		Domain:   "googleapis.com",
+		Provider: types.TypeGCP,
+	}
+
+	instanceVolumes, err := p.fetchInstanceVolumes(ctx, instanceIds...)
+	if err != nil {
+		return nil, fmt.Errorf("fetching volumes: %w", err)
+	}
+	state.InstanceVolumes = instanceVolumes
+
+	return state, nil
+}
+
+// fetchInstanceVolumes retrieves instance volumes from https://docs.cloud.google.com/compute/docs/reference/rest/v1/disks/aggregatedList
+func (p *Provider) fetchInstanceVolumes(ctx context.Context, instanceIds ...string) (map[string][]types.Volume, error) {
+	instanceVolumes := make(map[string][]types.Volume, len(instanceIds))
+
+	if len(instanceIds) == 0 {
+		return instanceVolumes, nil
+	}
+
+	instanceUrlsMap := make(map[string]string, len(instanceIds))
+	for _, instanceId := range instanceIds {
+		url := buildInstanceUrlFromId(instanceId)
+		if url == "" {
+			p.log.WithField("instance_id", instanceId).Warn("could not build instance url")
+			continue
+		}
+		instanceUrlsMap[url] = instanceId
+	}
+
+	filter := buildDisksUsedByInstanceFilter(lo.Keys(instanceUrlsMap))
+
+	req := &computepb.AggregatedListDisksRequest{
+		Project: p.cfg.GCPProjectID,
+		Filter:  &filter,
+	}
+
+	it := p.disksClient.AggregatedList(ctx, req)
+	for result, err := range it.All() {
+		if errors.Is(err, iterator.Done) {
+			break
+		}
+
+		if err != nil {
+			return instanceVolumes, fmt.Errorf("listing disks: %w", err)
+		}
+
+		for _, disk := range result.Value.Disks {
+			if disk.GetName() == "" {
+				p.log.Error("disk missing name, skipping")
+				continue
+			}
+
+			for _, instanceUrl := range disk.Users {
+				instanceId, ok := instanceUrlsMap[instanceUrl]
+				if !ok {
+					continue
+				}
+
+				volume := types.Volume{
+					VolumeID:    disk.GetName(),
+					VolumeState: strings.ToLower(disk.GetStatus()),
+					Encrypted:   true, // GCP disks are encrypted by default
+				}
+
+				if disk.GetType() != "" {
+					volume.VolumeType = path.Base(disk.GetType())
+				}
+
+				if disk.GetZone() != "" {
+					volume.Zone = path.Base(disk.GetZone())
+				}
+
+				if disk.GetSizeGb() > 0 {
+					// Size is in GB, convert to bytes
+					volume.SizeBytes = disk.GetSizeGb() * 1024 * 1024 * 1024
+				}
+
+				if disk.GetProvisionedIops() > 0 {
+					volume.IOPS = safeInt64ToInt32(disk.GetProvisionedIops())
+				}
+
+				if disk.GetProvisionedThroughput() > 0 {
+					// Throughput is in MB/s, convert to bytes/s
+					volume.ThroughputBytes = safeInt64ToInt32(disk.GetProvisionedThroughput() * 1024 * 1024)
+				}
+
+				instanceVolumes[instanceId] = append(instanceVolumes[instanceId], volume)
+			}
+		}
+	}
+
+	return instanceVolumes, nil
+}
+
+// buildInstanceUrlFromId converts an instance ID (project/zone/instance-name) to a full GCP instance URL
+func buildInstanceUrlFromId(instanceId string) string {
+	parts := strings.Split(instanceId, "/")
+	if len(parts) != 3 {
+		return ""
+	}
+	return fmt.Sprintf("https://www.googleapis.com/compute/v1/projects/%s/zones/%s/instances/%s", parts[0], parts[1], parts[2])
+}
+
+// buildDisksUsedByInstanceFilter builds a GCP API filter for disks attached to specific instances
+func buildDisksUsedByInstanceFilter(instanceUrls []string) string {
+	conditions := make([]string, len(instanceUrls))
+	for i, url := range instanceUrls {
+		conditions[i] = fmt.Sprintf(`(users:%q)`, url)
+	}
+	return strings.Join(conditions, " OR ")
+}
+
+func safeInt64ToInt32(val int64) int32 {
+	if val > math.MaxInt32 {
+		return math.MaxInt32
+	}
+	return int32(val) // nolint:gosec
 }
diff --git a/pkg/cloudprovider/gcp/test/env.example b/pkg/cloudprovider/gcp/test/env.example
index 47f6c999..169d22f3 100644
--- a/pkg/cloudprovider/gcp/test/env.example
+++ b/pkg/cloudprovider/gcp/test/env.example
@@ -4,6 +4,10 @@ GCP_PROJECT_ID=
 # Required: Your network (VPC) name to test
 NETWORK_NAME=
 
+# Required: GCP Instance ID to test volume listing
+# Example: my-gcp-project/us-east4-a/my-gcp-pool-3556b234,my-gcp-project/us-east4-c/my-gcp-pool-a7579587
+GCP_INSTANCE_IDS=
+
 # Optional: Path to service account key file
 # If not set, will use GOOGLE_APPLICATION_CREDENTIALS or default credentials
 GCP_CREDENTIALS_FILE=
diff --git a/pkg/cloudprovider/gcp/test/integration_test.go b/pkg/cloudprovider/gcp/test/integration_test.go
index 4823176d..a0cb5da4 100644
--- a/pkg/cloudprovider/gcp/test/integration_test.go
+++ b/pkg/cloudprovider/gcp/test/integration_test.go
@@ -5,6 +5,7 @@ package integration_test
 import (
 	"context"
 	"os"
+	"strings"
 	"testing"
 
 	"github.com/joho/godotenv"
@@ -84,3 +85,53 @@ func TestRefreshNetworkState(t *testing.T) {
 	}
 	// t.Logf("  Service Ranges: %+v", state.ServiceRanges)
 }
+
+// TestGetStorageState calls GetStorageState and prints the results.
+func TestGetStorageState(t *testing.T) {
+	cfg := getTestConfig(t)
+	ctx := t.Context()
+
+	provider, err := gcp.NewProvider(ctx, cfg)
+	if err != nil {
+		t.Fatalf("NewProvider failed: %v", err)
+	}
+
+	p := provider.(*gcp.Provider)
+
+	instanceIDsStr := os.Getenv("GCP_INSTANCE_IDS")
+	if instanceIDsStr == "" {
+		t.Fatal("GCP_INSTANCE_IDS not set")
+	}
+
+	instanceIDs := strings.Split(instanceIDsStr, ",")
+	for i := range instanceIDs {
+		instanceIDs[i] = strings.TrimSpace(instanceIDs[i])
+	}
+
+	state, err := p.GetStorageState(ctx, instanceIDs...)
+	if err != nil {
+		t.Fatalf("GetStorageState failed: %v", err)
+	}
+
+	for _, instanceID := range instanceIDs {
+		t.Logf("Testing instance: %s", instanceID)
+
+		volumes, ok := state.InstanceVolumes[instanceID]
+		if !ok {
+			t.Fatalf("No volumes found for instance %s", instanceID)
+		}
+
+		t.Logf("Found %d volumes attached to instance %s:", len(volumes), instanceID)
+		for _, v := range volumes {
+			t.Logf("  Volume:")
+			t.Logf("    VolumeID: %s", v.VolumeID)
+			t.Logf("    VolumeType: %s", v.VolumeType)
+			t.Logf("    VolumeState: %s", v.VolumeState)
+			t.Logf("    SizeBytes: %d", v.SizeBytes)
+			t.Logf("    Zone: %s", v.Zone)
+			t.Logf("    Encrypted: %v", v.Encrypted)
+			t.Logf("    IOPS: %d", v.IOPS)
+			t.Logf("    ThroughputBytes: %d B/s", v.ThroughputBytes)
+		}
+	}
+}