ABSTRACT: Attention deficit hyperactivity disorder (ADHD), is one of the four syndromes of minimal brain dysfunction, recongnized by the last classification of the Diagnostic and Statistical Manual of Mental Disorder (DSM IV). It is mainly characterized by attention deficit, hyperactivity, a low-level frustration, impulsivity, and emotional labilit. Although there are no doubts about its organic naure, the presence of this syndrome does not mean a demonstrable cerebral or irreversible lesion, but an alteration in high cerebral function, particulary in the area of behaviour. ADHD can be associated with language, learning, and motor disabilities. Diagnosis should be made on the basis of behaviour. ADHD can be associated with language, learning, and motor disabilities. Neuroimaging and neurophysiological studies are required only to exclude another phatoogies. Stimulants are the first choice in the treatment of ADHD, mainly methylphenidate, because it is well tolerated and improves not only the attention level and hyperactivity, but also learning and writing abilites. Prognosis varies acording to the severity of the clinical picture, early diagnosis and the familial interaction on the social context of child. Approximately 5% of infantile schoool pupulation have ADHD; therefore, this diagnostic possiblity should be considered by neuropediatricians and pediatricians for early diagnosis and treatment.