Background. Suicide prevention is a primary goal of mental health care and a past history of suicide attempts is considered a high-risk factor for subsequent attempts. This study aims to evaluate the effectiveness of an intensive suicide-reattempt-prevention program (ISRPP) in a health catchment area of 430.000 inhabitants. Methods. A 12-month follow-up study was conducted with all individuals who, between 1 January 2013 and 31 December 2015, had attempted suicide and sought mental health care in the area. Out of a total of 871 patients treated, 292 received treatment as part of ISRPP using short-term problem-solving therapy and a case management approach. Results were compared to those of 357 patients who received treatment as usual (TAU). Results. Attempted suicide was repeated by 9,0% in the ISRPP group, compared to 23,3% in the TAU (Fisher’s exact test p<0,001). The number needed to treat (NNT) was=7; 95% CI 95% (5-11). A multivariate Cox regression analysis showed that the TAU group had a hazard ratio (HR)=2,68; 95% CI (1,65-4,35) compared to the ISRPP group. The advantage of ISRPP was maintained when controlling for the non-homogeneous characteristics of the groups. Conclusions. Applied after a suicide attempt, an intensive prevention programme based on brief cognitive behavioural therapy (CBT) and case management reduces and delays repeat suicide attempts at one-year follow-up. The clinical effort is remarkable (NNT=7).