This article presents the results of research investigating the relation between interpersonal factors and personality disorders and intra-familial versus extra-familial child molesters. The sample contained 41 intra-familial and 43 extra-familial child molesters as well as a matched comparison group of 80 subjects. The analysis of the research results show that interpersonal factors, such as parental sensitivity, trust, and adult romantic attachment, discriminate between intra-familial and extra-familial child molesters. These findings structure the heterogeneous field of child molesters, as intra-familial child molesting seems to be related to relational attitude as well as personality disorders, whereas extra-familial child molesting is mainly related to personality disorders without showing significant deficits in the interpersonal factors that were measured. These results contribute to the explanation of this deviant sexual conduct and to the development and differentiation of the treatment of child molesters.