diff --git a/dotnet/src/Microsoft.Agents.AI/OpenTelemetryAgent.cs b/dotnet/src/Microsoft.Agents.AI/OpenTelemetryAgent.cs
index 35f4287514..c5507c1c62 100644
--- a/dotnet/src/Microsoft.Agents.AI/OpenTelemetryAgent.cs
+++ b/dotnet/src/Microsoft.Agents.AI/OpenTelemetryAgent.cs
@@ -229,24 +229,46 @@ public sealed class OpenTelemetryAgent : DelegatingAIAgent, IDisposable
         }
 
         string? sourceName = this._sourceName;
-        IChatClient WrapWithOpenTelemetry(IChatClient cc) =>
-            cc.AsBuilder().UseOpenTelemetry(sourceName: sourceName).Build();
+        static IChatClient WrapIfNeeded(IChatClient cc, string? sourceName) =>
+            cc.GetService(typeof(OpenTelemetryChatClient)) is not null
+                ? cc
+                : cc.AsBuilder().UseOpenTelemetry(sourceName: sourceName).Build();
 
         if (options is ChatClientAgentRunOptions ccOptions)
         {
             // Don't mutate the caller's options; clone and chain any caller-provided factory.
+            // If the user factory already returns an OpenTelemetry-instrumented client, don't double-wrap.
             var clone = (ChatClientAgentRunOptions)ccOptions.Clone();
             var userFactory = clone.ChatClientFactory;
-            clone.ChatClientFactory = cc => WrapWithOpenTelemetry(userFactory is null ? cc : userFactory(cc));
+            clone.ChatClientFactory = cc => WrapIfNeeded(userFactory is null ? cc : userFactory(cc), sourceName);
             return clone;
         }
 
-        return new ChatClientAgentRunOptions
+        // For a plain AgentRunOptions (or null), create a ChatClientAgentRunOptions and preserve
+        // any base AgentRunOptions properties from the caller so they reach the inner agent.
+        var newOptions = new ChatClientAgentRunOptions
         {
-            ChatClientFactory = WrapWithOpenTelemetry,
+            ChatClientFactory = cc => WrapIfNeeded(cc, sourceName),
         };
+
+        if (options is not null)
+        {
+            CopyBaseAgentRunOptions(options, newOptions);
+        }
+
+        return newOptions;
     }
 
+#pragma warning disable MEAI001 // ContinuationToken is experimental; copy it through to preserve caller-provided value.
+    private static void CopyBaseAgentRunOptions(AgentRunOptions source, AgentRunOptions target)
+    {
+        target.ContinuationToken = source.ContinuationToken;
+        target.AllowBackgroundResponses = source.AllowBackgroundResponses;
+        target.AdditionalProperties = source.AdditionalProperties?.Clone();
+        target.ResponseFormat = source.ResponseFormat;
+    }
+#pragma warning restore MEAI001
+
     /// <summary>The stub <see cref="IChatClient"/> used to delegate from the <see cref="OpenTelemetryChatClient"/> into the inner <see cref="AIAgent"/>.</summary>
     /// <param name="parentAgent"></param>
     private sealed class ForwardingChatClient(OpenTelemetryAgent parentAgent) : IChatClient
diff --git a/dotnet/tests/Microsoft.Agents.AI.UnitTests/OpenTelemetryAgentTests.cs b/dotnet/tests/Microsoft.Agents.AI.UnitTests/OpenTelemetryAgentTests.cs
index 28e192bc35..4a998f6b8f 100644
--- a/dotnet/tests/Microsoft.Agents.AI.UnitTests/OpenTelemetryAgentTests.cs
+++ b/dotnet/tests/Microsoft.Agents.AI.UnitTests/OpenTelemetryAgentTests.cs
@@ -792,6 +792,75 @@ public class OpenTelemetryAgentTests
         Assert.Contains(activities, a => string.Equals(a.GetTagItem("gen_ai.operation.name") as string, "chat", StringComparison.Ordinal));
     }
 
+    [Fact]
+    public async Task AutoWireChatClient_PlainAgentRunOptions_PreservesBaseProperties_Async()
+    {
+        // Auto-wiring converts a plain AgentRunOptions into a ChatClientAgentRunOptions. The base
+        // properties (ContinuationToken, AllowBackgroundResponses, AdditionalProperties, ResponseFormat)
+        // must be preserved so they reach the inner agent.
+        AgentRunOptions? observedOptions = null;
+        var fakeChatClient = new AutoWireTestChatClient();
+        var innerChatClientAgent = new ChatClientAgent(fakeChatClient);
+
+        // Wrapping agent: surfaces the ChatClientAgent via GetService (so auto-wiring activates),
+        // but captures the AgentRunOptions passed to RunAsync by the OpenTelemetryAgent.
+        var wrapper = new TestAIAgent
+        {
+            GetServiceFunc = (type, key) =>
+                type == typeof(ChatClientAgent) ? innerChatClientAgent : null,
+            RunAsyncFunc = (messages, session, options, ct) =>
+            {
+                observedOptions = options;
+                return Task.FromResult(new AgentResponse(new ChatMessage(ChatRole.Assistant, "ok")));
+            },
+        };
+
+        using var agent = new OpenTelemetryAgent(wrapper);
+
+        var additionalProps = new AdditionalPropertiesDictionary { ["customKey"] = "customValue" };
+        var inputOptions = new AgentRunOptions
+        {
+            AllowBackgroundResponses = true,
+            AdditionalProperties = additionalProps,
+            ResponseFormat = ChatResponseFormat.Json,
+        };
+
+        _ = await agent.RunAsync("hi", options: inputOptions);
+
+        Assert.NotNull(observedOptions);
+        Assert.IsType<ChatClientAgentRunOptions>(observedOptions);
+        Assert.Equal(true, observedOptions!.AllowBackgroundResponses);
+        Assert.Same(ChatResponseFormat.Json, observedOptions.ResponseFormat);
+        Assert.NotNull(observedOptions.AdditionalProperties);
+        Assert.Equal("customValue", observedOptions.AdditionalProperties!["customKey"]);
+    }
+
+    [Fact]
+    public async Task AutoWireChatClient_UserFactoryReturnsInstrumentedClient_DoesNotDoubleWrap_Async()
+    {
+        var sourceName = Guid.NewGuid().ToString();
+        var activities = new List<Activity>();
+        using var tracerProvider = OpenTelemetry.Sdk.CreateTracerProviderBuilder()
+            .AddSource(sourceName)
+            .AddInMemoryExporter(activities)
+            .Build();
+
+        var fakeChatClient = new AutoWireTestChatClient();
+        var inner = new ChatClientAgent(fakeChatClient);
+        using var agent = new OpenTelemetryAgent(inner, sourceName);
+
+        // User factory wraps the chat client with OpenTelemetryChatClient itself.
+        var runOptions = new ChatClientAgentRunOptions
+        {
+            ChatClientFactory = cc => cc.AsBuilder().UseOpenTelemetry(sourceName: sourceName).Build(),
+        };
+
+        _ = await agent.RunAsync("hi", options: runOptions);
+
+        // Expect 2 activities (invoke_agent + a single chat span). If we double-wrapped, we would see 3.
+        Assert.Equal(2, activities.Count);
+    }
+
     private sealed class AutoWireTestChatClient : IChatClient
     {
         public Task<ChatResponse> GetResponseAsync(IEnumerable<ChatMessage> messages, ChatOptions? options = null, CancellationToken cancellationToken = default) =>