Iron deficiency anemia and child mortality are public health problems requiring urgent attention. However, the degree to which iron deficiency anemia contributes to child mortality is unknown. Here, we utilized an exhaustive article search and screening process to identify articles containing both anemia and mortality data for children aged 28 days to 12 years. We then estimated the reduction in risk of mortality associated with a 1-g/dL increase in hemoglobin (Hb). Our meta-analysis of nearly 12,000 children from six African countries revealed a combined odds ratio of 0.76 (0.62–0.93), indicating that for each 1-g/dL increase in Hb, the risk of death falls by 24%. The feasibility of a 1-g/dL increase in Hb has been demonstrated via simple iron supplementation strategies. Our finding suggests that ~1.8 million deaths in children aged 28 days to five years could be avoided each year by increasing Hb in these children by 1 g/dL.