diff --git a/src/__phutil_library_map__.php b/src/__phutil_library_map__.php
--- a/src/__phutil_library_map__.php
+++ b/src/__phutil_library_map__.php
@@ -877,7 +877,6 @@
     'DiffusionIdentityUnassignedDatasource' => 'applications/diffusion/typeahead/DiffusionIdentityUnassignedDatasource.php',
     'DiffusionIdentityViewController' => 'applications/diffusion/controller/DiffusionIdentityViewController.php',
     'DiffusionInlineCommentController' => 'applications/diffusion/controller/DiffusionInlineCommentController.php',
-    'DiffusionInlineCommentPreviewController' => 'applications/diffusion/controller/DiffusionInlineCommentPreviewController.php',
     'DiffusionInternalAncestorsConduitAPIMethod' => 'applications/diffusion/conduit/DiffusionInternalAncestorsConduitAPIMethod.php',
     'DiffusionInternalGitRawDiffQueryConduitAPIMethod' => 'applications/diffusion/conduit/DiffusionInternalGitRawDiffQueryConduitAPIMethod.php',
     'DiffusionLastModifiedController' => 'applications/diffusion/controller/DiffusionLastModifiedController.php',
@@ -3594,7 +3593,6 @@
     'PhabricatorInfrastructureTestCase' => '__tests__/PhabricatorInfrastructureTestCase.php',
     'PhabricatorInlineComment' => 'infrastructure/diff/interface/PhabricatorInlineComment.php',
     'PhabricatorInlineCommentController' => 'infrastructure/diff/PhabricatorInlineCommentController.php',
-    'PhabricatorInlineCommentPreviewController' => 'infrastructure/diff/PhabricatorInlineCommentPreviewController.php',
     'PhabricatorInlineSummaryView' => 'infrastructure/diff/view/PhabricatorInlineSummaryView.php',
     'PhabricatorInstructionsEditField' => 'applications/transactions/editfield/PhabricatorInstructionsEditField.php',
     'PhabricatorIntConfigType' => 'applications/config/type/PhabricatorIntConfigType.php',
@@ -6968,7 +6966,6 @@
     'DiffusionIdentityUnassignedDatasource' => 'PhabricatorTypeaheadDatasource',
     'DiffusionIdentityViewController' => 'DiffusionController',
     'DiffusionInlineCommentController' => 'PhabricatorInlineCommentController',
-    'DiffusionInlineCommentPreviewController' => 'PhabricatorInlineCommentPreviewController',
     'DiffusionInternalAncestorsConduitAPIMethod' => 'DiffusionQueryConduitAPIMethod',
     'DiffusionInternalGitRawDiffQueryConduitAPIMethod' => 'DiffusionQueryConduitAPIMethod',
     'DiffusionLastModifiedController' => 'DiffusionController',
@@ -10115,7 +10112,6 @@
       'PhabricatorMarkupInterface',
     ),
     'PhabricatorInlineCommentController' => 'PhabricatorController',
-    'PhabricatorInlineCommentPreviewController' => 'PhabricatorController',
     'PhabricatorInlineSummaryView' => 'AphrontView',
     'PhabricatorInstructionsEditField' => 'PhabricatorEditField',
     'PhabricatorIntConfigType' => 'PhabricatorTextConfigType',
diff --git a/src/applications/diffusion/application/PhabricatorDiffusionApplication.php b/src/applications/diffusion/application/PhabricatorDiffusionApplication.php
--- a/src/applications/diffusion/application/PhabricatorDiffusionApplication.php
+++ b/src/applications/diffusion/application/PhabricatorDiffusionApplication.php
@@ -140,8 +140,6 @@
 
         'inline/' => array(
           'edit/(?P<phid>[^/]+)/' => 'DiffusionInlineCommentController',
-          'preview/(?P<phid>[^/]+)/'
-            => 'DiffusionInlineCommentPreviewController',
         ),
         'services/' => array(
           'path/' => array(
diff --git a/src/applications/diffusion/controller/DiffusionInlineCommentPreviewController.php b/src/applications/diffusion/controller/DiffusionInlineCommentPreviewController.php
deleted file mode 100644
--- a/src/applications/diffusion/controller/DiffusionInlineCommentPreviewController.php
+++ /dev/null
@@ -1,32 +0,0 @@
-<?php
-
-final class DiffusionInlineCommentPreviewController
-  extends PhabricatorInlineCommentPreviewController {
-
-  protected function loadInlineComments() {
-    $viewer = $this->getViewer();
-
-    return PhabricatorAuditInlineComment::loadDraftComments(
-      $viewer,
-      $this->getCommitPHID());
-  }
-
-  protected function loadObjectOwnerPHID() {
-    $viewer = $this->getViewer();
-
-    $commit = id(new DiffusionCommitQuery())
-      ->setViewer($viewer)
-      ->withPHIDs(array($this->getCommitPHID()))
-      ->executeOne();
-    if (!$commit) {
-      return null;
-    }
-
-    return $commit->getAuthorPHID();
-  }
-
-  private function getCommitPHID() {
-    return $this->getRequest()->getURIData('phid');
-  }
-
-}
diff --git a/src/infrastructure/diff/PhabricatorInlineCommentPreviewController.php b/src/infrastructure/diff/PhabricatorInlineCommentPreviewController.php
deleted file mode 100644
--- a/src/infrastructure/diff/PhabricatorInlineCommentPreviewController.php
+++ /dev/null
@@ -1,47 +0,0 @@
-<?php
-
-abstract class PhabricatorInlineCommentPreviewController
-  extends PhabricatorController {
-
-  abstract protected function loadInlineComments();
-  abstract protected function loadObjectOwnerPHID();
-
-  public function processRequest() {
-    $request = $this->getRequest();
-    $viewer = $request->getUser();
-
-    $inlines = $this->loadInlineComments();
-    assert_instances_of($inlines, 'PhabricatorInlineComment');
-
-    $engine = new PhabricatorMarkupEngine();
-    $engine->setViewer($viewer);
-    foreach ($inlines as $inline) {
-      $engine->addObject(
-        $inline,
-        PhabricatorInlineComment::MARKUP_FIELD_BODY);
-    }
-    $engine->process();
-
-    $phids = array($viewer->getPHID());
-    $handles = $this->loadViewerHandles($phids);
-    $object_owner_phid = $this->loadObjectOwnerPHID();
-
-    $views = array();
-    foreach ($inlines as $inline) {
-      $view = id(new PHUIDiffInlineCommentDetailView())
-        ->setUser($viewer)
-        ->setInlineComment($inline)
-        ->setMarkupEngine($engine)
-        ->setHandles($handles)
-        ->setEditable(false)
-        ->setPreview(true)
-        ->setCanMarkDone(false)
-        ->setObjectOwnerPHID($object_owner_phid);
-      $views[] = $view->render();
-    }
-    $views = phutil_implode_html("\n", $views);
-
-    return id(new AphrontAjaxResponse())
-      ->setContent($views);
-  }
-}