This article studies early childhood health in India, Bangladesh, and Nepal, focusing on inequalities in anthropometric outcomes by religious adherence. India and Nepal have Hindu majorities, while Bangladesh is predominantly Muslim. The results suggest that Muslim infants have an advantage over Hindu infants in height‐for‐age in India (for boys and girls) and in Bangladesh (for boys). However, this advantage disappears beyond 12 months of age, at which point Hindu children in all three countries are found to have significantly better anthropometric outcomes than Muslim children. We report tests that rule out mortality selection and undertake falsification and robustness exercises that confirm these findings. Further results suggest that exposure to Ramadan fasting in utero may lead to positive selection of Muslim male infants, partially explaining the Muslim infant health advantage, but this does not fully explain the shift from Muslim advantage in infancy to Hindu advantage in childhood in all three countries.