The relationship between maternal vitamin A deficiency during pregnancy and infant mortality is unclear. We conducted a prospective cohort study of 377 HIV-negative women and their infants in Blantyre, Malawi. Serum vitamin A levels were measured during the second or third trimester of pregnancy and infants were followed during the first year of life. From delivery until 12 months of age, 18 infants died (47.7 per 1000). Mothers of infants who died had lower serum vitamin A levels during pregnancy (0.74 +/- 0.13 mumol/l) compared with mothers of infants who did not die (1.02 +/- 0.03 mumol/l) (p = 0.055). Infants born to women whose vitamin A levels were in the lowest quartile (< 0.32 mumol/l) had three-fold higher likelihood of mortality than infants born to women whose vitamin A levels were in the higher quartiles (p < 0.03). These results suggest that maternal vitamin A deficiency during pregnancy may contribute to higher infant mortality rates.