This study expands the empirical and theoretical understanding of the distinction between those who perpetrate sexual assaults against children (child molesters) and those who perpetrate them against adults (rapists). Two questionnaires were completed by 88 incarcerated, male sexual offenders (45 child molesters and 43 rapists): the Spielberger state trait anxiety inventory and the Buss-Durkee hostility inventory. It was found that the rapists' level of aggression was significantly higher than that of the child molesters. No significant differences in anxiety levels were found between the two groups. The results are discussed in terms of their relevance to theory and clinical practice.