This article focuses on adolescent sexual behaviour and reasons leading to an early introduction to sexual life. The many types of adolescent sexual behaviour, the reasons for adolescents indulging in the sexual act, the use of contraceptives and the prevalence of sexually transmitted diseases (STDs) among them are examined. A baseline survey was conducted in Thiruvananthapuram, Kochi, and Kozhikode in Kerala state, and 825 children were identified to be engaged in the sex trade. The methods used were observation, focus group discussions and interviews with key informants and informal discussions and interviews with experts on adolescent sex workers (ASWs). The study found that a complex interplay of economic, social, cultural, religious, familial, psychological and environmental factors led the children into the sex trade. The children are mainly from a poor economic background. Penury and inharmonious family relations are the main factors that drive children into a life of social depravity. The most exploited ASWs are those who operate in streets and lodges. Most ASWs are at the mercy of caretakers and pimps who abuse the children physically and monetarily. Their awareness of the consequence of pregnancies, abortions, sexual health, STDs, AIDS and HIV is very poor. The study recommends that awareness should be created among ASWs regarding their sexual health and among all social strata on issues like gender roles, sexual and domestic violence, communication and negotiation skills.