Background: Men´s violence against women in relationship is a global healthproblem. 30% of all women in the world have at some point been exposed to violence in relationships. The problem tends to increase despite attempts to prevent the problem. Aim: The aim of this study is to achieve a deeper knowledge of prevention work to prevent violence against women in relationships. Methods: The study is based on six individual qualitative interviews with criminal investigative within the police and therapists in prison. Crime prevention models are used to analyze the qualitative interviews. Results: The results from this study show that poor self-esteem is a major risk factor for men´s violence against women in relationships. The criminal investigative och therapist agreed that the problem must be tackled at an early age. Conclusion: We need to start working and strengthening individs poor self-esteem at an early age through social crime prevention. When men have reached the stage where they are subject of the judiciary, the violence has often lasted a long time and the men have extensive problems.