BACKGROUND: The effect of a parent's death on the survival of the children has been assessed in only a few studies. We therefore investigated the effect of the death of the mother or father on the survival of the child up to age 10 years in rural Bangladesh. METHODS: We used data from population surveillance during 1982-2005 in Matlab, Bangladesh. We used Kaplan-Meier and Poisson regression analyses to compute the cumulative probabilities of survival and rates of age-specific death up to age 10 years, according to the survival status of the mother or father during that period. FINDINGS: There were 144 861 livebirths, and 14 868 children died by 10 years of age. The cumulative probability of survival to age 10 years was 24% in children whose mothers died (n=1385) before their tenth birthday, compared with 89% in those whose mothers remained alive (n=143 473). The greatest effect was noted in children aged 2-5 months whose mothers had died (rate ratio 25.05, 95% CI 18.57-33.81). The effect of the father's death (n=2691) on cumulative probability of survival of the child up to 10 years of age was negligible. Age-specific death rates did not differ in children whose fathers died compared with children whose fathers were alive. INTERPRETATION: The devastating effects of the mother's death on the survival of the child were most probably due to the abrupt cessation of breastfeeding, but the persistence of the effects up to 10 years of age suggest that the absence of maternal care might be a crucial factor. FUNDING: US Agency for International Development, UK Department for International Development, Research Program Consortium, and National Institutes of Health Fogarty International Center.