diff --git a/src/Explorer/Tabs/QueryTab.html b/src/Explorer/Tabs/QueryTab.html
index e27a4bb7c..ff4b40b06 100644
--- a/src/Explorer/Tabs/QueryTab.html
+++ b/src/Explorer/Tabs/QueryTab.html
@@ -11,6 +11,17 @@
       Start by writing a Mongo query, for example: <strong>{'id':'foo'}</strong> or <strong>{ }</strong> to get all the
       documents.
     </div>
+    <div class="warningErrorContainer" aria-live="assertive" data-bind="visible: maybeSubQuery">
+      <div class="warningErrorContent">
+        <span><img class="paneErrorIcon" src="/info_color.svg" alt="Error"/></span>
+        <span class="warningErrorDetailsLinkContainer">
+          We have detected you may be using a subquery. Non-correlated subqueries are not currently supported.
+          <a href="https://docs.microsoft.com/en-us/azure/cosmos-db/sql-query-subquery"
+            >Please see Cosmos sub query documentation for further information</a
+          >
+        </span>
+      </div>
+    </div>
     <div class="queryEditorWithSplitter" data-bind="attr: { id: queryEditorId }">
       <editor
         class="queryEditor"
diff --git a/src/Explorer/Tabs/QueryTab.ts b/src/Explorer/Tabs/QueryTab.ts
index 6a6d11007..f8bd4ed7f 100644
--- a/src/Explorer/Tabs/QueryTab.ts
+++ b/src/Explorer/Tabs/QueryTab.ts
@@ -1,5 +1,4 @@
 import * as ko from "knockout";
-import Q from "q";
 import * as Constants from "../../Common/Constants";
 import * as DataModels from "../../Contracts/DataModels";
 import * as ViewModels from "../../Contracts/ViewModels";
@@ -7,7 +6,6 @@ import { Action } from "../../Shared/Telemetry/TelemetryConstants";
 import TabsBase from "./TabsBase";
 import { HashMap } from "../../Common/HashMap";
 import * as HeadersUtility from "../../Common/HeadersUtility";
-import * as Logger from "../../Common/Logger";
 import { Splitter, SplitterBounds, SplitterDirection } from "../../Common/Splitter";
 import * as TelemetryProcessor from "../../Shared/Telemetry/TelemetryProcessor";
 import ExecuteQueryIcon from "../../../images/ExecuteQuery.svg";
@@ -31,6 +29,7 @@ export default class QueryTab extends TabsBase implements ViewModels.WaitsForTem
   public fetchNextPageButton: ViewModels.Button;
   public saveQueryButton: ViewModels.Button;
   public initialEditorContent: ko.Observable<string>;
+  public maybeSubQuery: ko.Computed<boolean>;
   public sqlQueryEditorContent: ko.Observable<string>;
   public selectedContent: ko.Observable<string>;
   public sqlStatementToExecute: ko.Observable<string>;
@@ -120,6 +119,11 @@ export default class QueryTab extends TabsBase implements ViewModels.WaitsForTem
       return (container && (container.isPreferredApiDocumentDB() || container.isPreferredApiGraph())) || false;
     });
 
+    this.maybeSubQuery = ko.computed<boolean>(function() {
+      const sql = this.sqlQueryEditorContent();
+      return sql && /.*\(.*SELECT.*\)/i.test(sql);
+    }, this);
+
     this.saveQueryButton = {
       enabled: this._isSaveQueriesEnabled,
       visible: this._isSaveQueriesEnabled