Data from Senegal's 1978 World Fertility Survey were used to demonstrate the decisive role of intermediate variables in the determination of general and marital fertility rates. Senegal's total fertility rate of 7.2 in 1974-78 indicates a high level of fertility which, moreover, appears to have changed little over time. Marital fertility is slightly higher than general fertility: married women had an average of 4.03 live births, vs. 3.53 for all women. A seemingly significant fertility differential by maternal educational status amounting to 1.34 child disappears when age and age at marriage are controlled. Age at marriage is a significant influence on fertility in the 1st 5 years of marriage, with fertility lower among women aged 15 or under at marriage. Abortion is a marginal practice in Senegal, and contraception is not widespread. 10% of ever married women reported having ever used a traditional method, and 1% a modern method. At the time of the survey only .5% used a modern method. Few significant differentials were noted in abortion or contraception by rural or urban residence. A slightly longer period of breastfeeding in rural areas (19.1 months vs. 17.6 months in urban areas) probably accounts for more of the slight rural-urban fertility differential than does abortion or contraception. Nuptiality in Senegal is early and intense, but is less stable than in most other African countries. The average age at 1st marriage of women aged 20-29 years was 16.4 for urban women, 15.6 for rural women, 17.0 for literate women, 15.7 for illiterate women, 16.0 for Wolofs, 15.1 for Poulars, 15.5 for Mandingos, 16.5 for Serers, 17.0 for Diolas, and 15.8 for the entire sample. Differences in age at marriage by rural or urban residence and women's educational level were more marked in younger cohorts. 95.6% of women aged 25-29 and 99.8% of those aged 30-34 at the time of the survey were already married. Age at marriage influences the propensity to divorce. 23.6% of marriages of women married at under 20 years vs. 19.1% of marriages of women over 20 ended in divorce. But 89% of divorced women subsequently remarried. Education, residence, and ethnic group also influenced the risk of divorce. 33% of Poular women, 27% of urban women, 27% of literate women, and 23% of Serer women ended their 1st unions in divorce. Wolof, Diola, and illiterate women had an average tendency to divorce, with 19% in each group terminating their 1st unions. 17% or rural women and 11% of Mandingo women divorced. Polygamy is widespread in Senegal. 48% of married women and 32% of married men are in polygamous unions. Senegal Fertility Survey data were limited to the current union, preventing a profound study of the interrelations between fertility and polygamy. But available data suggest that there are no fertility differences between monogamous and polygamous women either in the early years of marriage or overall. But divorce is much more likely for women infertile in the 1st years of marriage.