In this contribution, the necessity and expediency, but also the limits of the application of psychodiagnostic methods within the scope of forensic-psychological-psychiatric expertises are briefly discussed. On the basis of an intelligence and personality-diagnostic routine programme (RAVEN-PM, MWT-B; FPI, PpKV and Giessen test), the findings obtained in the examination of about 600 culprits who had been subjected to an expertise are presented. Test-psychological examination methods can and should reasonably supplement expertises in foro, but they will only gain their informative value and importance from the connection with the anamnesis, the content of the records, the exploration of the personality, of deed and deed experience of the person on whom expert opinion was given and the large range of neuropsychiatric diagnostic methods.