The current article criticizes the medical diagnostic construction of the Attention-Deficit/Hyperactivity Disorder, pointing out that this discourse relies on an ideal deficit presented nowadays as a hegemonic point of view. Due to it, the present article proposes a return to the main clinical characteristics arisen by the above mentioned field with the aim to discuss it with the regard of the psychoanalyses' conceptual theory. A child's diagnostic evaluation is presented. Our hypothesis that the "difference" in children with a diagnosis of Attention-Deficit/Hyperactivity Disorder, goes in the direction of a non-decided structural organization; which surrounds the clinical structures - neuroses, psychoses and perversion - ; indicating a bordering subjective position, on the limit of such structures.