Introduction: The National Board of Health and Welfares conclusion was that today there was a low awareness about children who act sexually toward others and how their problems can be handled. This requires extensive work by school personnel and social workers to give the children the support they need. Aim: The aim was to investigate social workers perception in cases concerning children and adolescents who committed sexual assault. Method: A qualitative method was utilized with semi-structured interviews to describe social workers perceptions in cases concerning children and adolescents who committed sexual assault. Four social workers from different communities were interviewed in southern Sweden. Results: The result described social workers experiences from working with these cases, investigations, treatments and preventative work. Analysis: The study shows that social worker experience the work with children and adolescents who committed sexual assault as difficult. It could be hard to decide which sexual behavior that was normal in the different ages. Teamwork between schools and social services are important to detect these cases. It is also important to work with children- and adolescent psychiatry and private companies that specialize in investigation and treatments in these cases. Conclusion: Children and adolescents who commit sexual assault seem to be an unknown area even within the social field. With more education to personnel who work with children and adolescents knowledge can be improved in this subject. The personnel need knowledge about which signs to be aware of.