This study presents an assessment of fertility trends in 23 countries of sub-Saharan Africa. It examines trends and differentials in proximate determinants and fertility preferences. Findings from the Demographic and Health Surveys for these countries over a period of 15 years show that desired family size has decreased significantly. Two-thirds of the countries examined show evidence of fertility decline, a particularly rapid decline in the cases of Kenya and Zimbabwe. Areas with higher education for women and lower child mortality experienced larger reductions in fertility and desired family size. Contraceptive use far exceeds other proximate determinants in explaining these changes. The striking regularity in fertility reduction across all ages indicates that contraception is practiced mostly for birth spacing and that contraceptive methods have gained wide acceptance among younger cohorts. Good prospects are seen for further intensification of fertility declines in East Africa and urban West Africa. However, low levels of education and high child mortality make rapid changes unlikely in rural West Africa.