The user-profile.tpl.php file won´t be recognized in my Drupal 7 installation
You could try adding your content in the user profile template preprocess function instead.

e.g, in template.php:

/**
 * Implements hook_preprocess_user_profile
 */
function THEMENAME_preprocess_user_profile(&amp;$variables) {
  // Fetch relevant user account
  $account = $variables['elements']['#account'];
  // Add content to user profile render array
  $variables['user_profile'][] = array(
    '#type' =&gt; 'markup', 
    '#markup' =&gt; 'Hello world'
  );
}


After adding a new preprocess function, clear theme registry cache, e.g at Admin &gt; Performance &gt; Clear all caches