diff --git a/src/applications/audit/query/PhabricatorCommitSearchEngine.php b/src/applications/audit/query/PhabricatorCommitSearchEngine.php
--- a/src/applications/audit/query/PhabricatorCommitSearchEngine.php
+++ b/src/applications/audit/query/PhabricatorCommitSearchEngine.php
@@ -59,6 +59,14 @@
       $query->withAuditAwaitingUser($this->requireViewer());
     }
 
+    $repository_phids = $saved->getParameter('repositoryPHIDs', array());
+    if ($repository_phids) {
+      // $repository_phids need to be mapped to $repository_ids via a subquery
+      // so make sure $viewer is set...!
+      $query->setViewer($this->requireViewer());
+      $query->withRepositoryPHIDs($repository_phids);
+    }
+
     return $query;
   }
 
@@ -71,11 +79,13 @@
       'commitAuthorPHIDs',
       array());
     $audit_status = $saved->getParameter('auditStatus', null);
+    $repository_phids = $saved->getParameter('repositoryPHIDs', array());
 
     $phids = array_mergev(
       array(
         $auditor_phids,
-        $commit_author_phids));
+        $commit_author_phids,
+        $repository_phids));
 
     $handles = id(new PhabricatorHandleQuery())
       ->setViewer($this->requireViewer())
@@ -100,7 +110,14 @@
          ->setName('auditStatus')
          ->setLabel(pht('Audit Status'))
          ->setOptions($this->getAuditStatusOptions())
-         ->setValue($audit_status));
+         ->setValue($audit_status))
+       ->appendChild(
+         id(new AphrontFormTokenizerControl())
+         ->setLabel(pht('Repositories'))
+         ->setName('repositoryPHIDs')
+         ->setDatasource(new DiffusionRepositoryDatasource())
+         ->setValue(array_select_keys($handles, $repository_phids)));
+
   }
 
   protected function getURI($path) {
diff --git a/src/applications/diffusion/query/DiffusionCommitQuery.php b/src/applications/diffusion/query/DiffusionCommitQuery.php
--- a/src/applications/diffusion/query/DiffusionCommitQuery.php
+++ b/src/applications/diffusion/query/DiffusionCommitQuery.php
@@ -60,6 +60,25 @@
   }
 
   /**
+   * Look up commits in a specific repository. Prefer
+   * @{method:withRepositoryIDs}; the underyling table is keyed by ID such
+   * that this method requires a separate initial query to map PHID to ID.
+   * Furthermore, this method requires calling @{method:setViewer} in
+   * advance due to the separate query.
+   */
+  public function withRepositoryPHIDs(array $phids) {
+    $repositories = id (new PhabricatorRepositoryQuery())
+      ->setViewer($this->getViewer())
+      ->withPHIDs($phids)
+      ->execute();
+
+    if (!$repositories) {
+      throw new PhabricatorEmptyQueryException();
+    }
+    $this->withRepositoryIDs(mpull($repositories, 'getID'));
+  }
+
+  /**
    * If a default repository is provided, ambiguous commit identifiers will
    * be assumed to belong to the default repository.
    *