Few studies have compared sexual behaviours among adolescents with high-functioning autism (HFA) and typical populations, and indicated whether specialized education is required. We hypothesized that adolescents with HFA would (1) display poorer social behaviours; (2) engage in fewer behaviours related to privacy and have poorer knowledge regarding privacy issues; (3) have less sex education; and (4) display more inappropriate sexual behaviours; and that (5) parental concerns would be greater for the HFA sample. Parents of typical adolescents (n = 50) and adolescents with HFA (n = 23) were surveyed with a Sexual Behaviour Scale (SBS) developed by the authors, with domains corresponding to the hypotheses. The HFA and typical groups were found to be significantly different on all five domains. However, following covariation with age and level of social behaviour, it was found that only parental concerns about their child distinguished between typical adolescents and those with HFA. Specialized sex education programmes with a social interaction emphasis should be considered for this group.