Background: This study investigated the relationship between family background and adolescent sexuality among secondary school students in Botswana.Objective: Controlling for individual, household, and community level variables, the main goals of the study are to determine the role of family background variables [at age 11, which significant adult did the subject live with, presence/absence of communication on sexuality with either co-resident and non-resident family members or both,presence/absence of punishment, for sexually-related behaviour, from resident adult family members] on awareness of HIV/AIDS and condom use among Secondary School students.Design: The study is cross-sectional and used a combination of both quantitative and qualitative methodologies. The main data source are the responses to the current and retrospective questions, obtained via self-administered questionnaires which were distributed among a selection of 531 students attending purposively selected SecondarySchools in Selibe-Phikwe, in 2001. Data from key informant interviews with Headmasters and other community leaders was also collected. This information was bolstered by that obtained from focus group discussions with the students. SPSS v-11.0 was employed to obtain bivariate analysis of the data, and to estimate logistic regressionequation of the likelihood of the dependent variable. These findings are interpreted in combination with the information obtained qualitatively.Results: Compared to living in a family of orientation that included both parents, living in a family of orientation that included “other” adults, other than mother, father, or grandparents, at age 11, significantly reduced the likelihood of condom use at first sexualencounter among adolescents. Also, communication on sexuality issues with a coresident parent significantly increased the likelihood of both HIV/AIDS awareness and condom use at first sexual encounter among adolescents. The likelihood of condom use increased very significantly when communication was with a grandparent than with aparent(s). On the other hand, punishment for sexually related behaviour by a resident adult family member significantly decreased the likelihood of condom use at first sexualencounter among adolescents.Conclusion: On the basis of these results, it is concluded that communication about sexual and reproductive health issues by significant adult family members with their children should be promoted.