diff --git a/src/Comment/CommentAdd/index.js b/src/Comment/CommentAdd/index.js
index bf6f92b..c258c98 100755
--- a/src/Comment/CommentAdd/index.js
+++ b/src/Comment/CommentAdd/index.js
@@ -1,12 +1,62 @@
 import React, { Component } from 'react';
 import { Mutation } from 'react-apollo';
 
+import { GET_COMMENTS_OF_ISSUE } from '../CommentList/queries';
 import { ADD_COMMENT } from './mutations';
 
 import TextArea from '../../TextArea';
 import Button from '../../Button';
 import ErrorMessage from '../../Error';
 
+const updateComments = ({
+  repositoryOwner,
+  repositoryName,
+  issue
+},
+client,
+{
+  data: {
+    addComment: {
+      commentEdge
+    }
+  }
+}
+) => {
+  const data = client.readQuery({
+    query: GET_COMMENTS_OF_ISSUE,
+    variables: {
+      repositoryOwner,
+      repositoryName,
+      number: issue.number
+    }
+  });
+
+  client.writeQuery({
+    query: GET_COMMENTS_OF_ISSUE,
+    variables: {
+      repositoryOwner,
+      repositoryName,
+      number: issue.number
+    },
+    data: {
+      ...data,
+      repository: {
+        ...data.repository,
+        issue: {
+          ...data.repository.issue,
+          comments: {
+            ...data.repository.issue.comments,
+            edges: [
+              ...data.repository.issue.comments.edges,
+              commentEdge
+            ]
+          }
+        }
+      }
+    }
+  })
+};
+
 class CommentAdd extends Component {
   state = {
     value: '',
@@ -23,13 +73,36 @@ class CommentAdd extends Component {
   };
 
   render() {
-    const { issueId } = this.props;
+    const { issue, repositoryOwner, repositoryName } = this.props;
     const { value } = this.state;
 
     return (
       <Mutation
         mutation={ADD_COMMENT}
-        variables={{ body: value, subjectId: issueId }}
+        variables={{ body: value, subjectId: issue.id }}
+        optimisticResponse={{
+          addComment: {
+            __typename: 'Mutation',
+            commentEdge: {
+              __typename: 'IssueCommentEdge',
+              node: {
+                __typename: 'IssueComment',
+                id: new Date().getTime() + '',
+                databaseId: new Date().getTime(),
+                author: {
+                  __typename: 'User',
+                  login: 'me'
+                },
+                bodyHTML: value
+              }
+            }
+          }
+        }}
+        update={(client, data) => updateComments({
+          repositoryOwner,
+          repositoryName,
+          issue
+        }, client, data)}
       >
         {(addComment, { data, loading, error }) => (
           <div>
diff --git a/src/Comment/CommentAdd/mutations.js b/src/Comment/CommentAdd/mutations.js
index 8e7dbea..01ae960 100755
--- a/src/Comment/CommentAdd/mutations.js
+++ b/src/Comment/CommentAdd/mutations.js
@@ -1,13 +1,16 @@
 import gql from 'graphql-tag';
 
+import ISSUECOMMENT_FRAGMENT from '../fragment';
+
 export const ADD_COMMENT = gql`
   mutation($subjectId: ID!, $body: String!) {
     addComment(input: { subjectId: $subjectId, body: $body }) {
       commentEdge {
         node {
-          body
+          ...issueComment
         }
       }
     }
   }
+  ${ISSUECOMMENT_FRAGMENT}
 `;
diff --git a/src/Comment/CommentList/index.js b/src/Comment/CommentList/index.js
index 41b5384..b156fdf 100755
--- a/src/Comment/CommentList/index.js
+++ b/src/Comment/CommentList/index.js
@@ -27,12 +27,19 @@ const updateQuery = (previousResult, { fetchMoreResult }) => {
           ...previousResult.repository.issue.comments,
           ...fetchMoreResult.repository.issue.comments,
           edges: [
-            ...previousResult.repository.issue.comments.edges,
-            ...fetchMoreResult.repository.issue.comments.edges,
-          ],
-        },
-      },
-    },
+            ...previousResult
+              .repository
+              .issue
+              .comments
+              .edges
+              .filter(
+                previousEdge => !fetchMoreResult.repository.issue.comments.edges.some(
+                  fetchMoreEdge => fetchMoreEdge.node.id === previousEdge.node.id)),
+            ...fetchMoreResult.repository.issue.comments.edges
+          ].sort((a, b) => a.node.databaseId - b.node.databaseId)
+        }
+      }
+    }
   };
 };
 
@@ -68,7 +75,11 @@ const Comments = ({ repositoryOwner, repositoryName, issue }) => (
             fetchMore={fetchMore}
           />
 
-          <CommentAdd issueId={repository.issue.id} />
+          <CommentAdd
+            issue={issue}
+            repositoryOwner={repositoryOwner}
+            repositoryName={repositoryName}
+          />
         </Fragment>
       );
     }}
diff --git a/src/Comment/CommentList/queries.js b/src/Comment/CommentList/queries.js
index 47b6cde..8967a8c 100755
--- a/src/Comment/CommentList/queries.js
+++ b/src/Comment/CommentList/queries.js
@@ -1,5 +1,7 @@
 import gql from 'graphql-tag';
 
+import ISSUECOMMENT_FRAGMENT from '../fragment';
+
 export const GET_COMMENTS_OF_ISSUE = gql`
   query(
     $repositoryOwner: String!
@@ -13,11 +15,7 @@ export const GET_COMMENTS_OF_ISSUE = gql`
         comments(first: 1, after: $cursor) {
           edges {
             node {
-              id
-              bodyHTML
-              author {
-                login
-              }
+              ...issueComment
             }
           }
           pageInfo {
@@ -28,4 +26,5 @@ export const GET_COMMENTS_OF_ISSUE = gql`
       }
     }
   }
+  ${ISSUECOMMENT_FRAGMENT}
 `;
diff --git a/src/Comment/fragment.js b/src/Comment/fragment.js
new file mode 100644
index 0000000..b784b78
--- /dev/null
+++ b/src/Comment/fragment.js
@@ -0,0 +1,12 @@
+import gql from 'graphql-tag';
+
+export default gql`
+  fragment issueComment on IssueComment {
+    id
+    databaseId
+    bodyHTML
+    author {
+      login
+    }
+  }
+`;
\ No newline at end of file