diff --git a/TaskTracker.Api/Controllers/TasksController.cs b/TaskTracker.Api/Controllers/TasksController.cs
index 17a776c..6b1ad7c 100644
--- a/TaskTracker.Api/Controllers/TasksController.cs
+++ b/TaskTracker.Api/Controllers/TasksController.cs
@@ -173,6 +173,13 @@ public class TasksController(ITaskRepository taskRepo, ILogger<TasksController>
         if (request.Description is not null) task.Description = request.Description;
         if (request.Category is not null) task.Category = request.Category;
         if (request.EstimatedMinutes.HasValue) task.EstimatedMinutes = request.EstimatedMinutes;
+        if (request.ParentTaskId.HasValue)
+        {
+            var parent = await taskRepo.GetByIdAsync(request.ParentTaskId.Value);
+            if (parent is null)
+                return BadRequest(ApiResponse.Fail("Parent task not found"));
+            task.ParentTaskId = request.ParentTaskId;
+        }
 
         await taskRepo.UpdateAsync(task);
         return Ok(ApiResponse<WorkTask>.Ok(task));
diff --git a/TaskTracker.Core/DTOs/UpdateTaskRequest.cs b/TaskTracker.Core/DTOs/UpdateTaskRequest.cs
index 24fd07e..b59059b 100644
--- a/TaskTracker.Core/DTOs/UpdateTaskRequest.cs
+++ b/TaskTracker.Core/DTOs/UpdateTaskRequest.cs
@@ -6,4 +6,5 @@ public class UpdateTaskRequest
     public string? Description { get; set; }
     public string? Category { get; set; }
     public int? EstimatedMinutes { get; set; }
+    public int? ParentTaskId { get; set; }
 }
diff --git a/TaskTracker.MCP/Tools/TaskTools.cs b/TaskTracker.MCP/Tools/TaskTools.cs
index 0226c7f..f7b51ba 100644
--- a/TaskTracker.MCP/Tools/TaskTools.cs
+++ b/TaskTracker.MCP/Tools/TaskTools.cs
@@ -39,9 +39,10 @@ public sealed class TaskTools
         HttpClient client,
         [Description("Title of the task")] string title,
         [Description("Optional description")] string? description = null,
-        [Description("Optional category (e.g. Engineering, Email, LaserCutting)")] string? category = null)
+        [Description("Optional category (e.g. Engineering, Email, LaserCutting)")] string? category = null,
+        [Description("Optional parent task ID to create this as a subtask")] int? parentTaskId = null)
     {
-        var payload = new { title, description, category };
+        var payload = new { title, description, category, parentTaskId };
         var response = await client.PostAsJsonAsync("/api/tasks", payload, JsonOptions);
         return await response.Content.ReadAsStringAsync();
     }