During the past 20 years, substantial reductions have occurred in the proportion of young women in sub-Saharan Africa who report that they married as teenagers. An often-stated consequence of a delay in age at marriage is a rise in the proportion of young women who engage in premarital sex. This article investigates the links between changing age at marriage and premarital sexual behavior in 27 sub-Saharan African countries in which Demographic and Health Surveys were conducted between 1994 and 2004. Using multiple-decrement life tables to examine the competing risks of premarital sex and marriage without prior sexual experience, we answer the largely unaddressed question of how reductions in the prevalence of early marriage have affected the likelihood of premarital sexual initiation. Our analysis reveals that although the age at first sexual activity has either remained the same or risen, a shift in the context of sexual initiation from marriage to before marriage has taken place in many countries. We assess whether the increase in the proportion of young women who report premarital sex is influenced by an increase in exposure resulting from delayed marriage or by an increase in the rate of premarital sex. The evidence on this point is mixed: in some settings greater exposure explains more of the increase, whereas in others an increased rate of premarital sex dominates.