diff --git a/dotnet/src/Microsoft.Agents.AI.Workflows/WorkflowChatHistoryProvider.cs b/dotnet/src/Microsoft.Agents.AI.Workflows/WorkflowChatHistoryProvider.cs
index 2815ed99f0..3f6656b994 100644
--- a/dotnet/src/Microsoft.Agents.AI.Workflows/WorkflowChatHistoryProvider.cs
+++ b/dotnet/src/Microsoft.Agents.AI.Workflows/WorkflowChatHistoryProvider.cs
@@ -62,6 +62,12 @@ internal sealed class WorkflowChatHistoryProvider : ChatHistoryProvider
         }
     }
 
+    public IEnumerable<ChatMessage> GetAllMessages(AgentSession session)
+    {
+        var state = this._sessionState.GetOrInitializeState(session);
+        return state.Messages;
+    }
+
     public void UpdateBookmark(AgentSession session)
     {
         var state = this._sessionState.GetOrInitializeState(session);
diff --git a/dotnet/src/Microsoft.Agents.AI.Workflows/WorkflowHostAgent.cs b/dotnet/src/Microsoft.Agents.AI.Workflows/WorkflowHostAgent.cs
index 7679123970..295c08ceeb 100644
--- a/dotnet/src/Microsoft.Agents.AI.Workflows/WorkflowHostAgent.cs
+++ b/dotnet/src/Microsoft.Agents.AI.Workflows/WorkflowHostAgent.cs
@@ -119,13 +119,17 @@ internal sealed class WorkflowHostAgent : AIAgent
         MessageMerger merger = new();
 
         await foreach (AgentResponseUpdate update in workflowSession.InvokeStageAsync(cancellationToken)
-                                                                      .ConfigureAwait(false)
-                                                                      .WithCancellation(cancellationToken))
+                                                                     .ConfigureAwait(false)
+                                                                     .WithCancellation(cancellationToken))
         {
             merger.AddUpdate(update);
         }
 
-        return merger.ComputeMerged(workflowSession.LastResponseId!, this.Id, this.Name);
+        AgentResponse response = merger.ComputeMerged(workflowSession.LastResponseId!, this.Id, this.Name);
+        workflowSession.ChatHistoryProvider.AddMessages(workflowSession, response.Messages);
+        workflowSession.ChatHistoryProvider.UpdateBookmark(workflowSession);
+
+        return response;
     }
 
     protected override async
@@ -138,11 +142,18 @@ internal sealed class WorkflowHostAgent : AIAgent
         await this.ValidateWorkflowAsync().ConfigureAwait(false);
 
         WorkflowSession workflowSession = await this.UpdateSessionAsync(messages, session, cancellationToken).ConfigureAwait(false);
+        MessageMerger merger = new();
+
         await foreach (AgentResponseUpdate update in workflowSession.InvokeStageAsync(cancellationToken)
                                                                       .ConfigureAwait(false)
                                                                       .WithCancellation(cancellationToken))
         {
+            merger.AddUpdate(update);
             yield return update;
         }
+
+        AgentResponse response = merger.ComputeMerged(workflowSession.LastResponseId!, this.Id, this.Name);
+        workflowSession.ChatHistoryProvider.AddMessages(workflowSession, response.Messages);
+        workflowSession.ChatHistoryProvider.UpdateBookmark(workflowSession);
     }
 }
diff --git a/dotnet/tests/Microsoft.Agents.AI.Workflows.UnitTests/WorkflowHostSmokeTests.cs b/dotnet/tests/Microsoft.Agents.AI.Workflows.UnitTests/WorkflowHostSmokeTests.cs
index 1920a57cb1..e61f4efe07 100644
--- a/dotnet/tests/Microsoft.Agents.AI.Workflows.UnitTests/WorkflowHostSmokeTests.cs
+++ b/dotnet/tests/Microsoft.Agents.AI.Workflows.UnitTests/WorkflowHostSmokeTests.cs
@@ -206,7 +206,7 @@ internal sealed class TurnTrackingStartExecutor : ChatProtocolExecutor
     }
 }
 
-public class WorkflowHostSmokeTests
+public class WorkflowHostSmokeTests : AIAgentHostingExecutorTestsBase
 {
     private sealed class AlwaysFailsAIAgent(bool failByThrowing) : AIAgent
     {
@@ -731,4 +731,26 @@ public class WorkflowHostSmokeTests
             .Should()
             .BeEmpty();
     }
+
+    [Fact]
+    public async Task Test_AsAgent_OutgoingMessagesInHistoryAsync()
+    {
+        // Arrange
+        TestReplayAgent agent = new(TestMessages, TestAgentId, TestAgentName);
+        Workflow handoffWorkflow = new HandoffsWorkflowBuilder(agent).Build();
+        AIAgent workflowAgent = handoffWorkflow.AsAIAgent();
+
+        // Act
+        AgentSession session = await workflowAgent.CreateSessionAsync();
+        AgentResponse response = await workflowAgent.RunAsync(session);
+
+        // Assert
+        WorkflowSession workflowSession = session.Should().BeOfType<WorkflowSession>().Subject;
+
+        ChatMessage[] responseMessages = response.Messages.ToArray();
+        ChatMessage[] sessionMessages = workflowSession.ChatHistoryProvider.GetAllMessages(workflowSession).ToArray();
+
+        // Since we never sent an incoming message, the expectation is that there should be nothing in the session
+        responseMessages.Should().BeEquivalentTo(sessionMessages);
+    }
 }