diff -u b/realname.drush.inc b/realname.drush.inc
--- b/realname.drush.inc
+++ b/realname.drush.inc
@@ -1,4 +1,5 @@
 <?php
+
 /**
  * @file
  * Realname module drush integration.
@@ -18,7 +19,7 @@
   $items = array();
 
   $items['realname-recreate'] = array(
-    'description' => "Recreate realnames on the site.",
+    'description' => 'Recreate realnames on the site.',
     'drupal dependencies' => array('realname'),
     'arguments' => array(
       'uid' => '(optional) A space-delimited list of User IDs',
@@ -53,7 +54,6 @@
   }
 }
 
-
 /**
  * Recreates realnames for specified (or all) users.
  *
@@ -69,40 +69,81 @@
   $args = func_get_args();
 
-  // If there are any arguments (at all) then they should all be UIDs.
+  $query = db_select('users');
+  $query->fields('users', array('uid'));
+  // No point updating the anonymous user.
+  $query->condition('uid', 0, '!=');
+
+  // Take into account the UIDs which were given.
   if (count($args)) {
-    $uids = array();
+    $query->condition('uid', $args, 'IN');
+  }
+
+  $uids = $query->execute()->fetchCol();
+
+  // Display info about UIDs which aren't valid.
+  if ($wrong_uids = array_diff($args, $uids)) {
+    drush_log(dt('Users with uids !uids do not exist and can\'t be updated.', array('!uids' => implode(', ', $wrong_uids))), 'error');
+  }
+
+  // Loop complete, it's possible there are no valid UIDs to update
+  if (!$uids) {
+    return drush_set_error(dt('No valid users available to update.'));
+  }
 
-    // Loop over each of the UIDs and check if the user account exists.
-    foreach ($args as $uid) {
-      if ($account = user_load($uid)) {
-        // Account exists, add the UID to our array.
-        $uids[] = $uid;
-      }
-      else {
-        // Account does not exist, let the user know.
-        drush_set_error('error', dt('User with UID #!uid does not exist.', array('!uid' => $uid)));
-      }
-    }
-
-    // Loop complete, it's possible there are no valid UIDs to update
-    if (empty($uids)) {
-      return drush_set_error(dt('No valid users available to update.'));
-    }
-  }
-  else {
-    // No UIDs defined, so we need to load all of the UIDs from {users}
-    $uids = db_select('users', 'u')
-      ->fields('u', array('uid'))
-      // no point updating the anonymous user.
-      ->condition('u.uid', 0, '!=')
-      ->execute()
-      ->fetchCol();
+  // Break up all of our data so each process does not time out.
+  $operations = array();
+  $chunks = array_chunk($uids, 100);
+  $count_chunks = count($chunks);
+
+  foreach ($chunks as $i => $chunk) {
+    $operations[] = array('realname_recreate', array(
+      $chunk,
+      'details'=> t('Updating chunk @chunk of @count', array(
+        '@chunk'=> $i + 1,
+        '@count'=> $count_chunks,
+      )),
+    ));
   }
 
-  // $uids now contains an array of users we know to exist.
-  realname_user_operations_realname_update($uids);
+  // Put all that information into our batch array.
+  $batch = array(
+    'operations' => $operations,
+    'title' => dt('Recreate realnames on the site.'),
+    'init_message' => dt('Initializing'),
+    'error_message' => dt('An unrecoverable error has occurred.'),
+    'finished' => 'realname_recreate_finished',
+  );
+
+  // Get the batch process all ready!
+  batch_set($batch);
+  $batch = &batch_get();
+
+  // Because we are doing this on the back-end, we set progressive to false.
+  $batch['progressive'] = FALSE;
 
+  // Start processing the batch operations.
+  drush_backend_batch_process();
+}
+
+/**
+ * Update the users.
+ */
+function realname_recreate($chunk, $operation_details, &$context) {
+  if (!isset($context['results']['updated'])) {
+    $context['results']['updated'] = 0;
+  }
+
+  realname_user_operations_realname_update($chunk);
+  $context['results']['updated'] += count($chunk);
+
+  $context['message'] = $operation_details;
+}
+
+/**
+ * Result message.
+ */
+function realname_recreate_finished($success, $results, $operations) {
   drush_log(dt('Updated realnames for !count users.', array(
-    '!count' => count($uids),
+    '!count' => $results['updated'],
   )), 'completed');
 }