BACKGROUND There are few studies on the prevalence of acne vulgaris among Asian teenagers. OBJECTIVE To determine the epidemiology of acne in teenagers in Singapore. METHODS A community-based cross-sectional study in 1045 adolescents aged 13-19 years. RESULTS Of these respondents, 88% identified themselves as having acne. Eight hundred and six of these respondents were examined by a dermatologist, and 51.4% were classified as having mild acne, 40% moderate acne and 8.6% severe acne. Isolation of Propionibacterium acnes was attempted in 262 subjects. Cultures were positive in 174 subjects, giving an isolation rate of 66.4%. Antibiotic-resistant strains of P. acnes were detected in 26 isolates (14.9%). Eleven of these 26 subjects (42%) had previously been treated or were presently on antibiotic treatment for acne, but the other 58% of students who had antibiotic-resistant strains of P. acnes did not give a history of prior antibiotic therapy. Teenagers expressed psychological distress over acne, and believed that hormonal factors, diet and hygiene were important factors in causing acne. CONCLUSIONS There is a need for accessible, accurate education on acne and its appropriate treatment.