The 44 men were referred to the Challenge Project, a community-based group treatment program for perpetrators of child sexual abuse. Subjects were referred for assessment either at the point of sentencing or when they were due to be considered for parole. Following referral, subjects were assessed in a semistructured clinical interview that covered personal and social details, a full history of offending behavior, and monitoring of attitudes toward the offense. Sociodemographic and background data obtained on the 44 perpetrators were largely compatible with those of previous research, including a significant history of childhood difficulties and sexual dysfunction in adulthood. The low intelligence, social class, and social skills observed may have been due to bias in cases coming to the attention of the legal system. There were clear subgroups of subjects with definite victim preferences. Those abusing boys were significantly more likely to have been a victim of childhood sexual abuse, reported a greater degree of psychosexual disturbance, and were charged more often for buggery offenses. Tentative data clusters for recidivist and incest subjects will be explored as the Challenge Project progresses, and individual and group outcomes of subjects accepted into the Challenge Project will be compared. 26 references and 2 tables