diff --git a/CHANGELOG.md b/CHANGELOG.md
index 9cbbe7aa3b..bfef4b9cff 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -42,6 +42,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ### Fixed
 
+- `opentelemetry-instrumentation-botocore`: bedrock: Add safety check for bedrock ConverseStream responses
+  ([#3990](https://github.com/open-telemetry/opentelemetry-python-contrib/pull/3990))
 - `opentelemetry-instrumentation-botocore`: bedrock: only decode JSON input buffer in Anthropic Claude streaming
   ([#3875](https://github.com/open-telemetry/opentelemetry-python-contrib/pull/3875))
 - `opentelemetry-instrumentation-aiohttp-client`, `opentelemetry-instrumentation-aiohttp-server`: Fix readme links and text
diff --git a/instrumentation/opentelemetry-instrumentation-botocore/src/opentelemetry/instrumentation/botocore/extensions/bedrock_utils.py b/instrumentation/opentelemetry-instrumentation-botocore/src/opentelemetry/instrumentation/botocore/extensions/bedrock_utils.py
index 2260d8ac73..0b164b1f92 100644
--- a/instrumentation/opentelemetry-instrumentation-botocore/src/opentelemetry/instrumentation/botocore/extensions/bedrock_utils.py
+++ b/instrumentation/opentelemetry-instrumentation-botocore/src/opentelemetry/instrumentation/botocore/extensions/bedrock_utils.py
@@ -528,7 +528,9 @@ def __init__(
     def from_converse(
         cls, response: dict[str, Any], capture_content: bool
     ) -> _Choice:
-        orig_message = response["output"]["message"]
+        # be defensive about malformed responses, refer to #3958 for more context
+        output = response.get("output", {})
+        orig_message = output.get("message", {})
         if role := orig_message.get("role"):
             message = {"role": role}
         else:
@@ -537,8 +539,8 @@ def from_converse(
 
         if tool_calls := extract_tool_calls(orig_message, capture_content):
             message["tool_calls"] = tool_calls
-        elif capture_content:
-            message["content"] = orig_message["content"]
+        elif capture_content and (content := orig_message.get("content")):
+            message["content"] = content
 
         return cls(message, response["stopReason"], index=0)
 
diff --git a/instrumentation/opentelemetry-instrumentation-botocore/tests/test_botocore_bedrock.py b/instrumentation/opentelemetry-instrumentation-botocore/tests/test_botocore_bedrock.py
index da8194c6a8..a8a0afe112 100644
--- a/instrumentation/opentelemetry-instrumentation-botocore/tests/test_botocore_bedrock.py
+++ b/instrumentation/opentelemetry-instrumentation-botocore/tests/test_botocore_bedrock.py
@@ -27,6 +27,7 @@
 
 from opentelemetry.instrumentation.botocore.extensions.bedrock_utils import (
     InvokeModelWithResponseStreamWrapper,
+    _Choice,
 )
 from opentelemetry.semconv._incubating.attributes.error_attributes import (
     ERROR_TYPE,
@@ -3051,6 +3052,16 @@ def stream_error_callback(exc, ended):
         assert "input" not in tool_block
 
 
+def test_converse_stream_with_missing_output_in_response():
+    # Test malformed response missing "output" key
+    malformed_response = {"stopReason": "end_turn"}
+    choice = _Choice.from_converse(malformed_response, capture_content=True)
+
+    assert choice.finish_reason == "end_turn"
+    assert choice.message == {}
+    assert choice.index == 0
+
+
 def amazon_nova_messages():
     return [
         {"role": "user", "content": [{"text": "Say this is a test"}]},