In group-living mammals, infants of females with strong social relationships sometimes exhibit higher survivorship than infants of less social females, a finding that holds true in our study population of wild white-faced capuchin monkeys. However, as in many mammals, new alpha male capuchins often kill young infants sired by other males. Our long-term research shows that infants of highly social females are at greater risk of dying or disappearing during periods of alpha male replacements than infants of less social females. These findings indicate that new alpha males are more likely to target the infants of more social, and therefore central, females. Our study provides evidence that female sociality can negatively affect offspring survival by increasing the likelihood of infanticide.