Does a day hospital format represent an adequate level of treatment for decompensated patients with personality disorders? The study concerns 97 consecutive patients, 50 of whom belonged to cluster A and B personality disorders. The patients were referred partly from an acute admission ward and partly from outpatient departments. The mean treatment time was approximately 6 months. The dropout rate for schizotypal and borderline patients was 38%. No patient committed suicide. Two patients made suicidal attempts during treatment. The level of medication was moderate, and 58% of the patients were drug-free at discharge. Treatment results at discharge, measured by SCL-90 and Health Sickness Rating Scale, were very good for patients with axis I disorders only, good for cluster C personality disorders, modest for borderline patients, and very modest for schizotypal patients. In general, the results indicate that the containing capacity of a day hospital therapeutic community is substantial and that it may reduce the need for long-term inpatient treatment.