This article describes the results of an eight-month follow-up investigation from a randomized controlled trial of day hospital psychotherapy (DHP) compared with outpatient individual psychotherapy (OIP) for patients with personality disorders (N=114). The patients were randomly assigned to either 18 weeks of day hospital treatment followed by long-term conjoint group and individual therapy (DHP), or outpatient individual psychotherapy (OIP). The main outcome measures were attrition rate, suicide attempts, suicidal thoughts, self-injury, psychosocial functioning, symptom distress, and interpersonal and personality problems. The study showed a low dropout rate and a moderate improvement on a broad range of clinical measures for both treatments. However, there was no indication of the superiority of one treatment over the other. Neither was there any indication that day hospital treatment was better for the most poorly functioning patients. Further studies will follow this group of patients for the next few years, the results of which may have implications for resource allocation and the organization of mental health services for patients with personality disorders.