When children and adolescents show deviant sexual behavior, co-operation between institutions of the youth welfare service is necessary in order to prevent further assaults. As a part of the Hamburg model project for minors who are at risk for sexual offending we evaluated the existing case-unspecific co-operation between the city's institutions. Selection of the sample resulted in a diagram of co-operation between institutions that have or might have contact to sexual deviant children or juveniles. By analyzing 147 online-surveys, comprising quantitative as well as qualitative questions, revealed a comprehensive system rich in resources but only little case-unspecific cooperation. Highest average rating in co-operation was given to the non-governmental institutions and the police. The inquiry of reasons for the co-operation indicated a demand for specialized diagnostics and advice. Positively evaluated were an efficient and fast processing, an unbureaucratic handling of the case and constant availability. Pointed out negatively were "not-reacting", trivializing and a lack of capacities. In order to improve the level of information and the range of intervention programs, training of professionals in school and the youth welfare service is needed.
