Using a massive malaria eradication program in India during the 1950s as a natural experiment, we examine the effects of disease environment on child health outcomes and fertility. We harmonise a rich dataset on malaria endemicity with fertility histories of women to exploit the cohort level variation in exposure to the program. We find that the program leads to a significant decline in infant and neonatal mortality and leads to a significant increase in the probability of birth during adolescent years in high malaria endemic regions. We confirm that a fall in the mother’s age at first birth in the post-eradication period drives the fertility response. © 2022 Informa UK Limited, trading as Taylor & Francis Group.