BACKGROUND: In the Netherlands compulsory admissions are on the increase. However, there are regional differences even when demographic factors are taken into account. AIM: To find out whether there are regional differences in the type and duration of care given to detainees. METHOD: On the basis of case-register data for Gronigen, South Limburg, Utrecht and Rotterdam, we monitored the psychiatric history and aftercare followed emergency compulsory admissions and we analysed the differences between patient groups ('old acquaintances', 'newcomers' and 'passers-by'). RESULTS: Almost 60% of patients were well known to the mental health care service and had previously received psychiatric care. 85% of the patients were still receiving care three months after admission. Even when patient and admission characteristics were taken into account, there were still regional variations in the type and length of mental health care episodes before and after compulsory admission. CONCLUSION: The continuity of health care for emergency admissions in the context of the Dutch Mental Health Act varies from region to region. It remains to be seen whether the situation will change when the new Mental Health Act comes into force.