The contribution of nutritional interventions to the reduction in maternal morbidity rates in developing countries is not well known. We assessed the impact of weekly vitamin A and beta-carotene supplementation on the prevalence of pregnancy and postpartum illness symptoms among 15,832 Nepali women in a placebo-controlled, double-masked, cluster-randomized trial. There was no impact of either supplement on morbidity rates reported up to 28 wk of gestation, inclusive. However, in late pregnancy (>28 wk), symptoms of nausea, faintness and night blindness were reduced with vitamin A, but not beta-carotene, supplementation. Vitamin A supplementation shortened the length of labor by 1.5 h 50 min among nulliparous and multiparous women, respectively. Both interventions reduced the postpartum prevalence of at least four loose stools and night blindness. beta-Carotene supplementation also reduced symptoms of high fever postpartum. The mean number of days of any reported illness symptoms was 3-4 per wk throughout pregnancy. Among women receiving vitamin A, the total number of days of illness symptoms accrued over the last 12 wk of pregnancy was lower by 5 d compared with the placebo recipients. We found the burden of pregnancy-related illness symptoms to be high in this rural area of Nepal where antenatal care is poor and most deliveries occur at home. Maternal vitamin A or beta-carotene supplementation resulted in a reduction in the prevalence of selected illness symptoms during late pregnancy, at the time of birth and during 6 mo postpartum, suggesting that a diet adequate in vitamin A may be important for improving women's reproductive health.