diff --git a/aio/tools/transforms/angular-base-package/index.js b/aio/tools/transforms/angular-base-package/index.js
index ab7020c6d3..890b480668 100644
--- a/aio/tools/transforms/angular-base-package/index.js
+++ b/aio/tools/transforms/angular-base-package/index.js
@@ -53,10 +53,11 @@ module.exports = new Package('angular-base', [
     inlineTagProcessor.inlineTagDefinitions.push(require('./inline-tag-defs/custom-search-defs/'));
   })
 
-  .config(function(checkAnchorLinksProcessor) {
-    // This is disabled here to prevent false negatives for the `docs-watch` task.
+  .config(function(checkAnchorLinksProcessor, checkForUnusedExampleRegions) {
+    // These are disabled here to prevent false negatives for the `docs-watch` task.
     // It is re-enabled in the main `angular.io-package`
     checkAnchorLinksProcessor.$enabled = false;
+    checkForUnusedExampleRegions.$enabled = false;
   })
 
   // Where do we get the source files?
diff --git a/aio/tools/transforms/angular.io-package/index.js b/aio/tools/transforms/angular.io-package/index.js
index 139937e839..dd53e65985 100644
--- a/aio/tools/transforms/angular.io-package/index.js
+++ b/aio/tools/transforms/angular.io-package/index.js
@@ -29,6 +29,12 @@ module.exports = new Package('angular.io', [gitPackage, apiPackage, contentPacka
     renderDocsProcessor.extraData.versionInfo = versionInfo;
   })
 
+  .config(function(checkForUnusedExampleRegions) {
+    // Re-enable this processor that was disabled in the `angular-base` package to
+    // avoid running it during `serve-and-sync` runs.
+    checkForUnusedExampleRegions.$enabled = true;
+  })
+
   .config(function(checkAnchorLinksProcessor, linkInlineTagDef, renderExamples) {
 
     // Fail the processing if there is an invalid link
diff --git a/aio/tools/transforms/examples-package/index.js b/aio/tools/transforms/examples-package/index.js
index 436cde974f..39da1cb346 100644
--- a/aio/tools/transforms/examples-package/index.js
+++ b/aio/tools/transforms/examples-package/index.js
@@ -13,6 +13,7 @@ module.exports =
 
         .processor(require('./processors/collect-examples'))
         .processor(require('./processors/render-examples'))
+        .processor(require('./processors/check-for-unused-example-regions'))
 
         .config(function(readFilesProcessor, exampleFileReader) {
           readFilesProcessor.fileReaders.push(exampleFileReader);
diff --git a/aio/tools/transforms/examples-package/processors/check-for-unused-example-regions.js b/aio/tools/transforms/examples-package/processors/check-for-unused-example-regions.js
new file mode 100644
index 0000000000..f94b4d78c7
--- /dev/null
+++ b/aio/tools/transforms/examples-package/processors/check-for-unused-example-regions.js
@@ -0,0 +1,38 @@
+/**
+ * @license
+ * Copyright Google LLC All Rights Reserved.
+ *
+ * Use of this source code is governed by an MIT-style license that can be
+ * found in the LICENSE file at https://angular.io/license
+ */
+
+/**
+ * A processor that will fail if there are named example regions that are not used in any docs.
+ *
+ * @param {*} exampleMap - contains all the regions extracted from example files.
+ */
+module.exports = function checkForUnusedExampleRegions(exampleMap) {
+  return {
+    $runAfter: ['renderExamples'],
+    $runBefore: ['writing-files'],
+    $process() {
+      const unusedExampleRegions = [];
+      for (const exampleFolder of Object.values(exampleMap)) {
+        for (const exampleFile of Object.values(exampleFolder)) {
+          for (const [regionName, region] of Object.entries(exampleFile.regions)) {
+            if (regionName === '' || region.usedInDoc) continue;
+            unusedExampleRegions.push(region);
+          }
+        }
+      }
+
+      if (unusedExampleRegions.length > 0) {
+        const message = (unusedExampleRegions.length === 1 ?
+                             'There is 1 unused example region:\n' :
+                             `There are ${unusedExampleRegions.length} unused example regions:\n`) +
+            unusedExampleRegions.map(region => ` - ${region.id}`).join('\n');
+        throw new Error(message);
+      }
+    },
+  };
+};
diff --git a/aio/tools/transforms/examples-package/processors/check-for-unused-example-regions.spec.js b/aio/tools/transforms/examples-package/processors/check-for-unused-example-regions.spec.js
new file mode 100644
index 0000000000..56021e38b2
--- /dev/null
+++ b/aio/tools/transforms/examples-package/processors/check-for-unused-example-regions.spec.js
@@ -0,0 +1,77 @@
+/**
+ * @license
+ * Copyright Google LLC All Rights Reserved.
+ *
+ * Use of this source code is governed by an MIT-style license that can be
+ * found in the LICENSE file at https://angular.io/license
+ */
+const testPackage = require('../../helpers/test-package');
+const Dgeni = require('dgeni');
+
+describe('checkForUnusedExampleRegions', () => {
+  var processor, exampleMap;
+
+  beforeEach(function() {
+    const dgeni = new Dgeni([testPackage('examples-package', true)]);
+    const injector = dgeni.configureInjector();
+    exampleMap = injector.get('exampleMap');
+    processor = injector.get('checkForUnusedExampleRegions');
+  });
+
+  describe('$process()', () => {
+    it('should error if there is a named example region which has not been used', () => {
+      exampleMap['examples'] = {
+        'some/file': {
+          regions: {
+            '': {id: 'some/file#'},
+            'used': {id: 'some/file#used', usedInDoc: {}},
+            'not-used': {id: 'some/file#not-used'},
+          }
+        }
+      };
+      expect(() => processor.$process())
+          .toThrowError('There is 1 unused example region:\n - some/file#not-used');
+    });
+
+    it('should not error if there are no example folders', () => {
+      expect(() => processor.$process()).not.toThrowError();
+    });
+
+    it('should not error if there are no example files', () => {
+      exampleMap['examples'] = {};
+      expect(() => processor.$process()).not.toThrowError();
+    });
+
+    it('should not error if there are no example regions', () => {
+      exampleMap['examples'] = {
+        'some/file': {
+          regions: {},
+        },
+      };
+      expect(() => processor.$process()).not.toThrowError();
+    });
+
+    it('should not error if there are no named example regions', () => {
+      exampleMap['examples'] = {
+        'some/file': {
+          regions: {
+            '': {id: 'some/file#'},
+          },
+        },
+      };
+      expect(() => processor.$process()).not.toThrowError();
+    });
+
+    it('should not error if there are no unused named example regions', () => {
+      exampleMap['examples'] = {
+        'some/file': {
+          regions: {
+            '': {id: 'some/file#'},
+            'used': {id: 'some/file#used', usedInDoc: {}},
+          }
+        }
+      };
+      expect(() => processor.$process()).not.toThrowError();
+    });
+  });
+});
diff --git a/aio/tools/transforms/examples-package/services/getExampleRegion.js b/aio/tools/transforms/examples-package/services/getExampleRegion.js
index 62defda9ba..94fd9274f9 100644
--- a/aio/tools/transforms/examples-package/services/getExampleRegion.js
+++ b/aio/tools/transforms/examples-package/services/getExampleRegion.js
@@ -1,4 +1,4 @@
-module.exports = function getExampleRegion(exampleMap, createDocMessage, collectExamples) {
+module.exports = function getExampleRegion(exampleMap, createDocMessage, collectExamples, log) {
   return function getExampleRegionImpl(doc, relativePath, regionName) {
     const EXAMPLES_FOLDERS = collectExamples.exampleFolders;
 
@@ -29,10 +29,12 @@ module.exports = function getExampleRegion(exampleMap, createDocMessage, collect
     var sourceCodeDoc = exampleFile.regions[regionName || ''];
     if (!sourceCodeDoc) {
       const message = createDocMessage('Missing example region... relativePath: "' + relativePath + '", region: "' + regionName + '".', doc) + '\n' +
-                      'Regions available are: ' + Object.keys(exampleFile.regions).map(function(region) { return '"' + region + '"'; }).join(', ');
+      'Regions available are: ' + Object.keys(exampleFile.regions).map(function(region) { return '"' + region + '"'; }).join(', ');
       throw new Error(message);
     }
 
+    sourceCodeDoc.usedInDoc = doc;
+    log.debug(`Example region ${sourceCodeDoc.id} used in ${doc.id}`);
     return sourceCodeDoc.renderedContent;
   };
 };
diff --git a/aio/tools/transforms/examples-package/services/getExampleRegion.spec.js b/aio/tools/transforms/examples-package/services/getExampleRegion.spec.js
index ba42d11805..362ff0a2cc 100644
--- a/aio/tools/transforms/examples-package/services/getExampleRegion.spec.js
+++ b/aio/tools/transforms/examples-package/services/getExampleRegion.spec.js
@@ -43,4 +43,15 @@ describe('getExampleRegion', () => {
     }).toThrowError('Ignored example file... relativePath: "filtered/path" - doc\n' +
                     'This example file exists but has been ignored by a rule, in "some/gitignore".');
   });
+
+  it('should mark the example as having been "used"', () => {
+    const doc1 = {};
+    const doc2 = {};
+    expect(exampleMap['examples']['test/url'].regions['region-1'].usedInDoc).toBeUndefined();
+    getExampleRegion(doc1, 'test/url', 'region-1');
+    expect(exampleMap['examples']['test/url'].regions['region-1'].usedInDoc).toBe(doc1);
+    expect(exampleMap['examples']['test/url'].regions[''].usedInDoc).toBeUndefined();
+    getExampleRegion(doc2, 'test/url');
+    expect(exampleMap['examples']['test/url'].regions[''].usedInDoc).toBe(doc2);
+  });
 });