OBJECTIVE: To determine the impact of caesarean section on fertility among women in sub-Saharan Africa. DESIGN: Analysis of standardised cross-sectional surveys (Demographic and Health Surveys). SETTING: Twenty-two countries in sub-Saharan Africa, 1993-2003. SAMPLE: A total of 35 398 women of childbearing age (15-49 years). METHODS: Time to subsequent pregnancy was compared by mode of delivery using Cox proportional hazards regression models. MAIN OUTCOME MEASURES: Natural fertility rates subsequent to delivery by caesarean section compared with natural fertility rates subsequent to vaginal delivery. RESULTS: The natural fertility rate subsequent to delivery by caesarean section was 17% lower than the natural fertility rate subsequent to vaginal delivery (hazard ratio = 0.83, 95% CI 0.73-0.96, P < 0.01; controlling for age, parity, level of education, urban/rural residence and young age at first intercourse). Caesarean section was also associated with prior fertility and desire for further children: among multiparous women, an interval > or =3 versus <3 years between the index birth and the previous birth was associated with higher odds of caesarean section at the index birth (OR = 1.4, 95% CI 1.1-1.7, P= 0.005); among all women, the odds of desiring further children were lower among women who had previously delivered by caesarean section (OR = 0.67, 95% CI 0.54-0.84, P < 0.001). Caesarean section did not appear to increase the risk of a subsequent pregnancy ending in miscarriage, abortion or stillbirth. CONCLUSIONS: Among women in sub-Saharan Africa, caesarean section is associated with lower subsequent natural fertility. Although this reflects findings from developed countries, the roles of pathological and psychological factors may be quite different because a much higher proportion of caesarean sections in sub-Saharan Africa are emergency procedures for maternal indication.