In the psychological literature there are not clear results regarding working memory deficits in children with Attention Deficit Hyperactivity Disorder (ADHD). The main goal of the present research was to study the relationship between visuo-spatial working memory (VSWM) and the difficulty to control for irrelevant information. Children attending third- and fifth-grades were presented with a task investigating working memory performances with visuo-spatial stimuli. Results confirmed the existence of an inhibitory control impairment only in children referred by teachers for ADHD. Furthermore, we found developmental differences between third and fifth- graders, demonstrating that VSWM difficulties could be partially due to a developmental retardation.