It is increasingly recognised that one-third to one-half of children diagnosed as having attention deficit/hyperactivity disorder (ADHD) continue to exhibit symptoms of the disorder into adulthood. The purpose of this study was to report on the demographic and clinical profile of 85 adults (50 men, 35 women) who presented with adult ADHD and meet DSM-IV criteria for the disorder. Patients underwent a diagnostic work-up consisting of medical, psychiatric and demographic evaluation. Deficits in educational and social competence could be demonstrated in more than one third of the patients. Male patients consulted the out-patient service on the average earlier than female patients. Only a small percentage of the population was pretreated in childhood or adolesence. Highest degrees of comorbidity were found for substance abuse and mood disorders. Anxiety disorders and personality disorders were also frequently present in ADHD patients. Patients remained predominantly in the special out-patient service, transfer to GPs was inhibited by the currently off-label use of the prescribed drugs. Guidelines need to be drawn up to establish handover from paediatric to adult ADHD care.