2,533 persons charged for serious criminal offences during the years 1980-93 were submitted for forensic psychiatric examination. The purpose of the examinations was to decide whether the person, because of his or her mental state at the time of the offence, was liable or not to prosecution. The three most common criminal offences were murder, arson resulting in potential murder and serious cases of sexual offence like paedophilia. There was a sharp increase in the number of forensically examined persons from 1980 to 1993. This reflects the increasing crime rates in Norway, particularly as regards sexual delinquency and violence. A majority of the clients had severe chronic drinking and/or drug problems. 27% of the females and 19% of the males were psychotic, mainly schizophrenic, at the time of the offence. 50-60% had serious personality disorders, mainly of antisocial and immature nature. All forensic reports are monitored by the Forensic Psychiatric Commission in order to secure the quality of forensic assessments. 85% of the reports were accepted. In a few cases the psychiatrists were asked to reconsider either parts of or the entire conclusion.