diff --git a/lib/angellist_api/client/messages.rb b/lib/angellist_api/client/messages.rb
index f2c5363..a6e30c9 100644
--- a/lib/angellist_api/client/messages.rb
+++ b/lib/angellist_api/client/messages.rb
@@ -41,6 +41,20 @@ def get_messages(options={})
       def post_messages(options={})
         post("1/messages", options)
       end
+
+      # Marks all messages for the current user in the given thread_ids as viewed.
+      # Returns an array of all affected thread_ids on success. Requires scope "message".
+      #
+      # @requires_authentication Yes
+      #
+      # @param ids [Array] IDs of the startups to fetch.
+      #
+      # @example Mark threads 1, 2, and 3 as read for the current user.
+      #   AngellistApi.post_mark_messages([1, 2, 3])
+      def post_mark_messages(thread_ids)
+        params = { :ids => thread_ids.join(',') }
+        post("1/messages/mark", params)
+      end
     end
   end
 end
diff --git a/spec/integration/messages_spec.rb b/spec/integration/messages_spec.rb
index fc2ff36..2f7e3c6 100644
--- a/spec/integration/messages_spec.rb
+++ b/spec/integration/messages_spec.rb
@@ -15,5 +15,10 @@
       thread.should have_key field
     end
   end
+
+  it 'marks messages as read for a user' do
+    read_messages = client.post_mark_messages([1, 2, 3])
+    read_messages.should include(1, 2, 3)
+  end
 end
 
diff --git a/spec/unit/lib/angellist_api/client/messages_spec.rb b/spec/unit/lib/angellist_api/client/messages_spec.rb
index 574b334..f82bffc 100644
--- a/spec/unit/lib/angellist_api/client/messages_spec.rb
+++ b/spec/unit/lib/angellist_api/client/messages_spec.rb
@@ -18,6 +18,14 @@
       client.post_messages(options).should == "success"
     end
   end
-  
+
+  describe "#post_mark_messages" do
+    it "posts to 1/messages/mark" do
+      options = { :some => "options" }
+      client.should_receive(:post).with("1/messages/mark", options).and_return("success")
+      client.post_mark_messages(options).should == "success"
+    end
+  end
+
 end