Early initiation of breastfeeding (EIBF) is considered one of the most cost-effective interventions for infant survival and well-being. This study aimed to examine the variations in, and determinants of, early initiation of breastfeeding among women in high and low neonatal mortality rate (NMR) settings in India using data from the fourth round of the National Family Health Survey conducted in 2015–16. At 35%, EIBF was found to be disproportionately low in the high NMR group of states compared with 52% in the low NMR group, with the national average being 44%. The chance of EIBF significantly increased if childbirth was vaginal, delivery took place in a health institution, the mother received breastfeeding advice and the birth was a planned one in both high and low NMR settings. In the high NMR group of states, the probability of initiating breastfeeding immediately after birth improved to a great extent if childbirth was assisted by a trained person and if the mother was exposed to any type of mass media. There is an urgent need to increase the access of mothers to breastfeeding advice during pregnancy and to increase their exposure to mass media, particularly in high NMR states. In addition, achieving universal access to institutional deliveries and deliveries assisted by a skilled birth attendant, especially in high NMR settings, and promoting early breastfeeding, especially in the case of Caesarean deliveries, would further improve the level of EIBF in the country as a whole. These interventions can potentially increase the prevalence of early initiation of breastfeeding and help India attain the neonatal mortality rate target of Sustainable Development Goal 3.