: It has been demonstrated that children with attention deficit and hyperactivity disorder (ADHD) have impairments in working memory (WM), and particularly its visuospatial component, responsible for academic underachievement. Furthermore, children with ADHD have difficulty in metacognition, and consequently use inappropriate strategies to control attention and impulsive behavior. The aim of the present study was to devise a training that combined individual exercises on visuospatial WM and group metacognitive activities capable of helping children with ADHD to ameliorate their performance in executive functioning tasks, and to contain their inattentive and hyperactive/impulsive behavior. : A combined training that focused on visuospatial WM and metacognition was administered to 12 children with a diagnosis of ADHD and 15 typically-developing children. Tasks on executive functions and questionnaires for parents and teachers were administered before and at the end of the training, and one month after the post-test. Specific short- and long-term training gains and transfer effects were examined. Effects of the training on parents' and teachers' ratings were also considered. : Specific gains and transfer effects were found at the post-test and long-term assessments in both typically-developing children and those with ADHD. Parents' and teachers' ratings also indicated an improvement in the symptomatic behavior of children with ADHD. : The results of this study have clinical and educational implications. A training that combines individual computerized visuospatial WM activities with metacognitive group reflection about useful strategies seems to produce promising results, helping children with ADHD to improve their executive functioning and behavioral problems.