The health risks of unsafe sexual behaviour among young people aged 15-24, the stage when sexual activity including risky sexual behaviour is likely to begin, has been receiving growing attention. Researchers are attempting to identify factors which influence young people’s sexual behaviour so that meaningful prevention and intervention programmes can be developed. Using the 2005 Zambia Sexual Behaviour Survey, this study examines the level and determinants of sexual behaviour measured according to age at first sex, age at first childbearing, and condom use at first sex, among young people in Zambia. A total sample of 2,813 young people, representing 57.16 percent females and 42.84 percent males, was chosen for the analysis. The study employed survival analysis techniques to examine the timing and determinants of first sex and first childbearing. In addition, logistic regression models were used to predict the drivers of condom use at first sex. The analysis established that age at first sex, age at first childbearing, and condom use at first sex among young people in Zambia differ by cohort, gender, urban/rural residence, marital status, educational attainment, and province of residence. The results show that more young women (69.15 percent) than young men (57.84 percent) had initiated sex aged 15-24 years; whereas 47.89 percent of young women aged 15-24 years reported having had a first birth. The level of condom use at first sex was less than a quarter for young men (23.63 percent) and young women (24.34 percent), posing serious health challenges. There was evidence that the strongest predictors of sexual debut among young men were current age, residing in Lusaka or Northern provinces, and living in a household with television; while current age and higher education were positively associated with condom use at first sex among young women. The important determinants of first childbearing were age at first sex, and educational attainment. Finally, being unmarried, with some level of education, residing in Eastern, Luapula, Lusaka or Northern provinces, and living in a household with piped water or flush toilet, were found to be critical predictors of condom use at first sex among young people. It was concluded that although Zambia has shown progress in delaying sexual debut and first childbearing, other areas such as condom use at first sex, show little change – indicating a need for renewed efforts in HIV and AIDS prevention and family planning programmes. / Thesis (M.A.)-University of KwaZulu-Natal, Durban, 2012.