diff --git a/autoload/controls/class.Tasks.php b/autoload/controls/class.Tasks.php
index 1030a81..664e124 100644
--- a/autoload/controls/class.Tasks.php
+++ b/autoload/controls/class.Tasks.php
@@ -342,6 +342,34 @@ class Tasks
     exit;
   }
 
+  static public function task_change_users() {
+    global $mdb, $user;
+
+    if ( !$user or $user['id'] != 1 ) {
+      echo json_encode( [ 'status' => 'error' ] );
+      exit;
+    }
+
+    $task_id = (int)\S::get( 'task_id' );
+    $users = \S::get( 'users' );
+
+    if ( !$task_id ) {
+      echo json_encode( [ 'status' => 'error' ] );
+      exit;
+    }
+
+    $mdb -> delete( 'task_user', [ 'task_id' => $task_id ] );
+
+    if ( is_array( $users ) and !empty( $users ) ) {
+      foreach ( $users as $uid ) {
+        $mdb -> insert( 'task_user', [ 'task_id' => $task_id, 'user_id' => (int)$uid ] );
+      }
+    }
+
+    echo json_encode( [ 'status' => 'success' ] );
+    exit;
+  }
+
   /**
    * @deprecated Use \Controllers\TasksController::taskChangeStatus() instead.
    */
@@ -450,7 +478,8 @@ class Tasks
       'clients' => \factory\Crm::get_client_list(),
       'user' => $user,
       'statuses' => \factory\Tasks::get_statuses(),
-      'projects' => \factory\Projects::user_projects( $user['id'] )
+      'projects' => \factory\Projects::user_projects( $user['id'] ),
+      'all_users' => \factory\Users::users_list()
     ] );
     exit;
   }
diff --git a/templates/tasks/task_popup.php b/templates/tasks/task_popup.php
index 726d2f9..b57f989 100644
--- a/templates/tasks/task_popup.php
+++ b/templates/tasks/task_popup.php
@@ -23,6 +23,9 @@
         <a href="#" class="js-task-tab-btn" data-tab="checklist" role="tab" aria-selected="false">Lista kontrolna (<?= (int)$checklist_count;?>)</a>
         <a href="#" class="js-task-tab-btn" data-tab="comments" role="tab" aria-selected="false">Komentarze (<?= (int)$comments_count;?>)</a>
         <a href="#" class="js-task-tab-btn" data-tab="attachments" role="tab" aria-selected="false">Za&#322;&#261;czniki (<?= (int)$attachments_count;?>)</a>
+        <? if ( $this -> user['id'] == 1 ):?>
+          <a href="#" class="js-task-tab-btn" data-tab="users" role="tab" aria-selected="false">Uczestnicy</a>
+        <? endif;?>
       </div>
       <div class="users box">
         <? if ( is_array( $this -> task['users'] ) ): foreach ( $this -> task['users'] as $user_tmp_id ):?>
@@ -109,6 +112,22 @@
           </ul>
         </div>
       </div>
+      <? if ( $this -> user['id'] == 1 ):?>
+        <div class="task-tab-panel" data-tab="users">
+          <div class="task-users-edit">
+            <h3>Uczestnicy</h3>
+            <div class="task-users-checkboxes">
+              <? if ( is_array( $this -> all_users ) ): foreach ( $this -> all_users as $u ):?>
+                <label class="task-user-label">
+                  <input type="checkbox" class="task-user-checkbox" value="<?= $u['id'];?>" <? if ( is_array( $this -> task['users'] ) and in_array( $u['id'], $this -> task['users'] ) ):?>checked="checked"<? endif;?>>
+                  <?= $u['name'] . ' ' . $u['surname'];?>
+                </label>
+              <? endforeach; endif;?>
+            </div>
+            <a href="#" class="btn btn-primary btn-sm js-save-task-users" task_id="<?= $this -> task['id'];?>" style="margin-top: 10px;">Zapisz</a>
+          </div>
+        </div>
+      <? endif;?>
     </div>
     <div class="right">
       <div class="status box">
@@ -285,6 +304,23 @@
     border-color: #6690f4;
   }
 
+  .task_popup .task_details .task-users-checkboxes {
+    display: flex;
+    flex-direction: column;
+    gap: 6px;
+  }
+  .task_popup .task_details .task-user-label {
+    display: flex;
+    align-items: center;
+    gap: 8px;
+    cursor: pointer;
+    padding: 4px 0;
+    font-size: 13px;
+  }
+  .task_popup .task_details .task-user-label input[type="checkbox"] {
+    margin: 0;
+  }
+
   /* Lightbox - powiększanie zdjęć w opisie */
   .task_popup .task_details .description img {
     cursor: zoom-in;
@@ -342,7 +378,7 @@
       if ( !tab_panels.length )
         return;
 
-      var allowed_tabs = [ 'description', 'checklist', 'comments', 'attachments' ];
+      var allowed_tabs = [ 'description', 'checklist', 'comments', 'attachments', 'users' ];
       var selected_tab = allowed_tabs.indexOf( tab_name ) >= 0 ? tab_name : 'description';
 
       tab_panels.each( function() {
@@ -429,6 +465,41 @@
       });
     });
 
+    popup.on( 'click', '.js-save-task-users', function( e ) {
+      e.preventDefault();
+      var btn = $( this );
+      var task_id = btn.attr( 'task_id' );
+      var users = [];
+      popup.find( '.task-user-checkbox:checked' ).each( function() {
+        users.push( $( this ).val() );
+      });
+      btn.text( 'Zapisywanie...' ).addClass( 'disabled' );
+      $.ajax({
+        type: 'POST',
+        url: '/tasks/task_change_users/',
+        data: { task_id: task_id, users: users },
+        success: function( response ) {
+          var res = typeof response === 'string' ? JSON.parse( response ) : response;
+          if ( res.status === 'success' ) {
+            var names = [];
+            popup.find( '.task-user-checkbox:checked' ).each( function() {
+              names.push( $( this ).parent().text().trim() );
+            });
+            var html = '';
+            for ( var i = 0; i < names.length; i++ ) {
+              var initials = names[i].split( ' ' ).map( function( w ) { return w[0]; } ).join( '' );
+              html += '<div class="user"><div class="avatar" title="' + names[i] + '">' + initials + '</div>' + names[i] + '</div>';
+            }
+            popup.find( '.users.box' ).html( html );
+            btn.text( 'Zapisano!' );
+          } else {
+            btn.text( 'Błąd' );
+          }
+          setTimeout( function() { btn.text( 'Zapisz' ).removeClass( 'disabled' ); }, 1500 );
+        }
+      });
+    });
+
     var interval_id = setInterval( function() {
       if ( !document.body.contains( popup.get( 0 ) ) )
       {