Family environment is one of the most influential factors on youth sexual behavior but has received little investigation in sub-Saharan Africa. Yet, a comprehensive understanding of family influences could improve the efficiency of reproductive health (RH) interventions. Using retrospective data from a population-based survey, life-table analysis was utilized to compute the median age at premarital intercourse among 1,182 youth aged 12-24 years. Discrete-time hazard models were used in multivariate analysis to estimate the effects of family structures and parent-child interactions on premarital intercourse. Overall, 42% of participants had a premarital intercourse, and the median age at first sex was 16.9 years. Participants in nuclear two-parent families had the highest median (17.7) compared with those in nuclear one-(16.7), extended one-(16.5), extended two-parent families (16.9) or other relatives (16.8). Youth from monogamous families had the highest median (16.9) compared to those from polygamous (16.3) and other families (16.0). Orphans and youth reporting family transitions were more likely to initiate first sex at an earlier age compared with non-orphans and non-movers, with a median of 16.1 and 16.9 years, respectively. Multivariate results showed that living in extended families, being orphaned, and family transitions significantly increased the risk of premarital intercourse. Polygamy showed marginal effects. Stronger parent-child relationships and higher levels of parental control decreased the risk of premarital intercourse. Unexpectedly, parent-child communication was significantly associated with a higher risk of sexual debut. Programmatically, family environment is an important resource that needs to be promoted when designing RH interventions in sub-Saharan Africa.