Attention Deficit/Hyperactivity Disorder (adhd) is the most frequent behavior disorder of childhood with a prevalence of 3-5%. adhd persists in at least 30% in adulthood, so the estimated prevalence of adhd in adults is 1%. Etiologically, genetic factors are the most important. In neuro-imaging, morphological abnormalities and dysfunction of the frontal cortex and basal ganglia have been established. There is little research in diagnostic assessment and treatment of adults. In this article, a proposal is made based on literature and own experience. Hetero-anamnestic information about childhood-onset of symptoms is being advised. Treatment can consist of psycho-education, medication (methylphenidate and desipramine are effective in controlled trials in adults), psychotherapy and supportgroups.