diff --git a/news/2 Fixes/5333.md b/news/2 Fixes/5333.md
new file mode 100644
index 000000000000..30f632405b25
--- /dev/null
+++ b/news/2 Fixes/5333.md	
@@ -0,0 +1 @@
+Restrict files from being processed by `Language Server` only when in a mult-root workspace.
\ No newline at end of file
diff --git a/src/client/activation/languageServer/analysisOptions.ts b/src/client/activation/languageServer/analysisOptions.ts
index caa9172c7e45..b6bbb4f8cab5 100644
--- a/src/client/activation/languageServer/analysisOptions.ts
+++ b/src/client/activation/languageServer/analysisOptions.ts
@@ -5,8 +5,8 @@
 
 import { inject, injectable, named } from 'inversify';
 import * as path from 'path';
-import { CancellationToken, CompletionContext, ConfigurationChangeEvent, Disposable, Event, EventEmitter, OutputChannel, Position, TextDocument } from 'vscode';
-import { LanguageClientOptions, ProvideCompletionItemsSignature, RevealOutputChannelOn } from 'vscode-languageclient';
+import { CancellationToken, CompletionContext, ConfigurationChangeEvent, Disposable, Event, EventEmitter, OutputChannel, Position, TextDocument, WorkspaceFolder } from 'vscode';
+import { DocumentFilter, DocumentSelector, LanguageClientOptions, ProvideCompletionItemsSignature, RevealOutputChannelOn } from 'vscode-languageclient';
 import { IWorkspaceService } from '../../common/application/types';
 import { isTestExecution, PYTHON_LANGUAGE, STANDARD_OUTPUT_CHANNEL } from '../../common/constants';
 import { traceDecorators, traceError } from '../../common/logger';
@@ -103,17 +103,10 @@ export class LanguageServerAnalysisOptions implements ILanguageServerAnalysisOpt
         this.excludedFiles = this.getExcludedFiles();
         this.typeshedPaths = this.getTypeshedPaths();
         const workspaceFolder = this.workspace.getWorkspaceFolder(this.resource);
-        const documentSelector = [
-            { scheme: 'file', language: PYTHON_LANGUAGE },
-            { scheme: 'untitled', language: PYTHON_LANGUAGE }
-        ];
-        if (workspaceFolder) {
-            // tslint:disable-next-line:no-any
-            (documentSelector[0] as any).pattern = `${workspaceFolder.uri.fsPath}/**/*`;
-        }
-        // Options to control the language client
+        const documentSelector = this.getDocumentSelector(workspaceFolder);
+        // Options to control the language client.
         return {
-            // Register the server for Python documents
+            // Register the server for Python documents.
             documentSelector,
             workspaceFolder,
             synchronize: {
@@ -148,6 +141,18 @@ export class LanguageServerAnalysisOptions implements ILanguageServerAnalysisOpt
             }
         };
     }
+    protected getDocumentSelector(workspaceFolder?: WorkspaceFolder): DocumentSelector {
+        const documentSelector: DocumentFilter[] = [
+            { scheme: 'file', language: PYTHON_LANGUAGE },
+            { scheme: 'untitled', language: PYTHON_LANGUAGE }
+        ];
+        // Set the document selector only when in a multi-root workspace scenario.
+        if (workspaceFolder && Array.isArray(this.workspace.workspaceFolders) && this.workspace.workspaceFolders!.length > 1) {
+            // tslint:disable-next-line:no-any
+            documentSelector[0].pattern = `${workspaceFolder.uri.fsPath}/**/*`;
+        }
+        return documentSelector;
+    }
     protected getExcludedFiles(): string[] {
         const list: string[] = ['**/Lib/**', '**/site-packages/**'];
         this.getVsCodeExcludeSection('search.exclude', list);
diff --git a/src/test/activation/languageServer/analysisOptions.unit.test.ts b/src/test/activation/languageServer/analysisOptions.unit.test.ts
index 9d452a048d7a..5a6fb078f30c 100644
--- a/src/test/activation/languageServer/analysisOptions.unit.test.ts
+++ b/src/test/activation/languageServer/analysisOptions.unit.test.ts
@@ -6,13 +6,15 @@
 import { expect } from 'chai';
 import { instance, mock, verify, when } from 'ts-mockito';
 import * as typemoq from 'typemoq';
-import { ConfigurationChangeEvent, Uri } from 'vscode';
+import { ConfigurationChangeEvent, Uri, WorkspaceFolder } from 'vscode';
+import { DocumentSelector } from 'vscode-languageclient';
 import { LanguageServerAnalysisOptions } from '../../../client/activation/languageServer/analysisOptions';
 import { LanguageServerFolderService } from '../../../client/activation/languageServer/languageServerFolderService';
 import { ILanguageServerFolderService } from '../../../client/activation/types';
 import { IWorkspaceService } from '../../../client/common/application/types';
 import { WorkspaceService } from '../../../client/common/application/workspace';
 import { ConfigurationService } from '../../../client/common/configuration/service';
+import { PYTHON_LANGUAGE } from '../../../client/common/constants';
 import { PathUtils } from '../../../client/common/platform/pathUtils';
 import { IConfigurationService, IDisposable, IExtensionContext, IOutputChannel, IPathUtils, IPythonExtensionBanner } from '../../../client/common/types';
 import { EnvironmentVariablesProvider } from '../../../client/common/variables/environmentVariablesProvider';
@@ -26,6 +28,9 @@ import { sleep } from '../../core';
 
 suite('Language Server - Analysis Options', () => {
     class TestClass extends LanguageServerAnalysisOptions {
+        public getDocumentSelector(workspaceFolder?: WorkspaceFolder): DocumentSelector {
+            return super.getDocumentSelector(workspaceFolder);
+        }
         public getExcludedFiles(): string[] {
             return super.getExcludedFiles();
         }
@@ -199,4 +204,43 @@ suite('Language Server - Analysis Options', () => {
 
         expect(settingsChangedInvokedCount).to.be.equal(1);
     });
+    test('Ensure search pattern is not provided when there are no workspaces', () => {
+        when(workspace.workspaceFolders).thenReturn([]);
+
+        const expectedSelector = [
+            { scheme: 'file', language: PYTHON_LANGUAGE },
+            { scheme: 'untitled', language: PYTHON_LANGUAGE }
+        ];
+
+        const selector = analysisOptions.getDocumentSelector();
+
+        expect(selector).to.deep.equal(expectedSelector);
+    });
+    test('Ensure search pattern is not provided in single-root workspaces', () => {
+        const workspaceFolder: WorkspaceFolder = { name: '', index: 0, uri: Uri.file(__dirname) };
+        when(workspace.workspaceFolders).thenReturn([workspaceFolder]);
+
+        const expectedSelector = [
+            { scheme: 'file', language: PYTHON_LANGUAGE },
+            { scheme: 'untitled', language: PYTHON_LANGUAGE }
+        ];
+
+        const selector = analysisOptions.getDocumentSelector(workspaceFolder);
+
+        expect(selector).to.deep.equal(expectedSelector);
+    });
+    test('Ensure search pattern is provided in a multi-root workspace', () => {
+        const workspaceFolder1 = { name: '1', index: 0, uri: Uri.file(__dirname) };
+        const workspaceFolder2 = { name: '2', index: 1, uri: Uri.file(__dirname) };
+        when(workspace.workspaceFolders).thenReturn([workspaceFolder1, workspaceFolder2]);
+
+        const expectedSelector = [
+            { scheme: 'file', language: PYTHON_LANGUAGE, pattern: `${workspaceFolder1.uri.fsPath}/**/*` },
+            { scheme: 'untitled', language: PYTHON_LANGUAGE }
+        ];
+
+        const selector = analysisOptions.getDocumentSelector(workspaceFolder1);
+
+        expect(selector).to.deep.equal(expectedSelector);
+    });
 });