In many countries deinstitutionalization of psychiatric patients is accompanied by fragmentation of care, giving responsibility to an array of different services and providers. One of the possible side effects of this is an increased rehospitalization rate and length of stay. The need to coordinate the services involved for the benefit of individuals has led to the conceptual development of case management. However, despite an apparent belief in the effectiveness of case management, there is only limited scientific evidence to support this assumption. In the case control study presented we compared a group of 97 schizophrenic patients in the aftercare of case management services with a group of patients who received no outpatient care by case management services after discharge from hospital. Each patient in the case-managed group was exactly matched with a control patient with regard to diagnosis and known risk factors for rehospitalization. Additionally, we considered influencing factors that result from general health system conditions such as regional differences and different types of hospital care. Our analyses demonstrate that, during an observation period of 2.5 years, case management had neither a significant effect on the risk of rehospitalization nor on the length of time in hospital in the event of rehospitalization.