Recent research on reproductive and sexual health has focused on age at marriage as a determinant of an array of population and health outcomes. We argue that, for many reproductive health concerns, it is not age at marriage that should be the focus of analysis but rather the number of years that have elapsed between sexual debut and marriage. This paper explores the factors associated with the length of the interval between initiation of sex and formation of a union in order to gain insight into this aspect of women’s reproductive lives.Using data from the 2004 Cameroon DHS, our sample consists of ever-marriedwomen between the ages of 19-34 (N= 4,681). Chi-square tests of difference were used inthe bivariate analysis while OLS regression was the multivariate method selected.Distributions by age at first sex and age at first union show that individual womenvary more by their age at marriage than by their age at first sex. The bivariate and multivariate analyses show that having a birth prior to first union, initiating sexual activity while still in school, number of lifetime partners, terminating a pregnancy, andpracticing contraception are associated with significantly longer intervals of premarital sexual activity.Women accrue both benefits and penalties when they have longer intervalsbetween sexual debut and union formation. Education is a critical benefit associated witha delay in marriage; however, the health penalties associated with such a delay can beconsiderable