Objective: The aim of the current study was to examine adolescents' perceptions of the quality of a Sex and Relationship Education (SRE) intervention, their preferences for sources of SRE and how these vary as a function of gender, school's faith and school type. Design: A non-experimental design was used. Setting: The participants (N = 759 adolescent girls [n = 448] and boys [n = 326]), who had attended an SRE intervention and had previously been given formal SRE within the school they attended, completed a survey questionnaire. Method: A questionnaire was designed to assess perceptions and preference of the intervention. The data were analysed using logistic regression. Results: Adolescents judged the sex education intervention to be of high quality and enjoyed being taught by sexual-health workers. Preferred sources of SRE included sexual-health workers, parents and peers as well as the media. Gender, school's faith (Church of England or Catholic) and school type (mainstream, special needs) were predictors of preference for various aspects of SRE. Conclusion: The results highlight the crucial role of experienced qualified SRE educators, but also the supplementary role of parents and peers as well as the auxiliary role of Internet sites, magazines, phone lines and schools. Stereotypical preferences of boys and girls outside SRE seem to be perpetuated in SRE, and special needs and mainstream adolescents' preferences are consistent with their communication and education outside SRE. (Contains 5 tables and 1 note.)