This is a theoretical and empirical paper to analyze possible bias against daughters in the provision of healthcare. Women once married become part of in-laws’ families, leading to certain inter-family externalities in household decision making, which in turn result in gender bias in healthcare. We test our theoretical predictions using LSMS household survey data from two Indian states, viz. Uttar Pradesh and Bihar. We find strong evidence for the existence of bias against daughters. We also find, consistent with our theory but contrary to conventional wisdom, that the bias is more pronounced among Hindu families (who tend to practice exogamy) than among Muslim families (who very commonly intermarry).