The four groups included 104 incarcerated adolescent sexual offenders between 10 and 15 years of age, 198 incarcerated sexual offenders between 16 and 20 years of age, 124 incarcerated youth without a history of sexual offending, and 135 male nonoffending undergraduates. Incarcerated youth were recruited in Ohio, Oregon, and Texas, while college students were recruited from introductory psychology classes at Ohio State University. Data were obtained from participants using the Sexual History Form and the Sexual Fantasy Questionnaire. Results showed young sexual offenders reported fewer consenting sexual experiences and more involvement in nonconsenting and paraphilic behaviors than both incarcerated nonsexual offenders and college males. Moreover, both sexual offenders and incarcerated nonsexual offenders reported more atypical and voyeuristic experiences and fewer nondeviant sexual fantasies than college males. Findings are discussed in terms of both social deficit and deviant conditioning models of sexual offending. The authors speculate that criminal activity may be associated with suppressed levels of nondeviant fantasies rather than with elevated levels of deviant fantasies. 24 references and 2 tables