Abstract Background. – In the 1980s, suicide rates in Denmark were among the highest in the world. In 1992, a Suicide Prevention Centre was opened in Copenhagen with a 2-week programme of social and psychological treatment. The aim of the study was to evaluate the effect of the Suicide Prevention Centre. Methods. – In a quasi-experimental study, 362 patients in the Suicide Prevention Centre and a parallel comparison group of 39 patients were interviewed with European Parasuicide Study Interviewer Schedule I (EPSIS I), which is a comprehensive interview including several validated scales. All patients were invited to follow-up interviews with EPSIS II and followed in the National Patients Register and the Cause of Death Register. Results. – At the 1-year follow-up, 59% of patients in the intervention group and 53% of patients in the comparison groups were interviewed with EPSIS II. The intervention group obtained a significantly greater improvement in Beck’s Depression Inventory, Hopelessness Scale, Rosenberg’s Self-Esteem Scale and CAGE-score and a significantly lower repetition rate. Discussion. – Although the design cannot exclude selection bias, it seems likely that the improvement in the intervention group was facilitated by the treatment.