This paper investigates whether boys receive preferential prenatal treatment in a setting where son preference is present. Using micro health data from India, we highlight sex-selective prenatal investments as a new channel via which parents practice discriminatory behavior. We find that mothers visit antenatal clinics and receive tetanus shots more frequently when pregnant with a boy. Preferential prenatal treatment of males is greater in regions known to have strong son preference and among women whose previous children are female. We address other mechanisms such as selective recall, medical complications that might cause male fetuses to receive greater prenatal care in general, son preference- based fertility stopping rules and biases due to sex-selective abortions. Our calculations suggest that sex- selective prenatal care in maternal tetanus vaccination explains between 2.6--7.2 percent of excess female neonatal mortality in India. (Contains 8 tables, 1 figure, and 30 footnotes.)