A recent modification of German law requires quality assurance of inpatient treatment, i.e., of the quality of therapy, allowing comparison of different hospitals. In this paper a program developed to assess the outcome by means of international, frequently applied psychopathometric scales is presented. This program was evaluated in a study of 258 psychiatric inpatients. This study emphasized the identification of patients with long-term hospitalization and/or worse outcome. A concept to disclose these so-called 'problematic' patients by means of easily administered scales like the SCL90-R, GAF and WHO-Disability-Diagnostic-Scale (DDS) has been developed. Patients with a very long hospital stay (> 70 days) show a higher number and more severe symptoms in the self-rating (SCL90-R) at admission than the subjects with a short hospital stay. This pilot study demonstrated that a routine outcome analysis can be used for quality management in psychiatry.