The participation of social work in inpatient psychiatric care is generally considered necessary, but there is a lack of empirical studies in this field. The analyses presented of a systematic documentation of social work interventions in 2038 cases during an 11-year period demonstrate that social workers are mostly involved in the treatment of chronic and previously treated patients. Interventions in younger patients, most of whom are suffering from psychoses, aim at rehabilitation through activity; in elderly patients with organic or depressive disorders, the major concern is to improve posthospital care; patients with neurotic or personality disorders comprise another group with a chronic course and a relatively poor outcome. As far as their goals are comparable, social workers and doctors agree on their objectives. Social workers usually see their own interventions as successful, but patient groups who benefit greatly can be differentiated from groups with poor outcome.