Purpose. The danger of stereotyping child sex offenders is that such stereotypes allow suspected abusers to avoid detection. The current study investigated whether professionals involved in the treatment of sex offenders endorsed less stereotypes of sex offenders than an ‘inexperienced’ group of teachers. Method. Sixty professionals involved with sex offenders and 71 school teachers completed three questionnaires: the Stereotypes of Sex Offenders Questionnaire; Attitudes Towards Sex Offenders Scale (Hogue, 1993) and Knowledge of Child Abuse Questionnaire (created for the present study). Mediation analyses were then conducted on the relationships between the scores. Results. Experienced professionals endorsed negative stereotypes less, had more positive attitudes towards sex offenders and expressed more knowledge of child abuse than the inexperienced group. Further, attitudes towards child sexual offenders were significantly mediated by the effect of knowledge of child abuse on group (experienced, inexperienced). However, there was no significant mediation for the effect of knowledge on child abuse on the relationship between group (experienced, inexperienced) and stereotype consistent scores. Conclusions. The less knowledge of child abuse, the more stereotypical one may be about potential child sex offenders. Thus, it may be useful to increase knowledge on child abuse in inexperienced groups to counter stereotyping and allow greater detection of offenders.