Disease environment and demographic change plays a critical role in determining the size and quality of human capital that drives the growth path of an economy. While broad patterns of demographic transition are understood there is a mixed evidence on the role of disease eradication in expediting demographic change. Using the massive malaria eradication program in India during the 1950's as a natural experiment, we examine the effect of disease environment on infant mortality and fertility response at household level. We harmonize a rich database 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 probability of birth in high malaria-endemic regions. We confirm the mechanism of fall in mother's age at first birth in post eradication period drives the fertility response.