Young people with perinatal HIV infection (PHIV+) engage in sexual risk behaviours that place their partners at high risk of infection, according to newly published data. PHIV+ youths aged 10–18 years completed a self interview. 28% of responders reported intercourse, 62% of whom reported having unprotected sex. Nonadherence to antiretroviral (ARV) treatment was associated with initiation of sexual activity and many of the participants were shown to be resistant to ARVs. Effective measures to educate PHIV+ young people and improve treatment adherence and safe sex practices are urgently needed.