Participatory Educational Theatre (PET) is an educational theatre methodology which uses a participatory approach to allow the audience to probe, reflect on and respond to issues which concern them. The article describes how PET was used as part of a CARE Kenya programme which works with young people to prevent and control sexually transmitted diseases and HIV. PET projects in two communities addressed issues of child and youth sexuality, modes of transmission and prevention, and barriers to the adoption of preventive measures. Although aimed originally at young people, in practice it proved impossible to separate young people from the village as a whole. The initiative proved highly successful and demonstrated the power of participatory drama for cutting through the cultural barriers to communication.