The extent of child undernutrition in India is quite high, its prevalence and incidence require explanation. Searches for socio-demographic and economic factors that affect child undernutrition in our country have been made in the literature, but those are exercises based on averages. Using the unit-level information obtainable from NFHS 3, NFHS 4 and NFHS 5, this paper makes an attempt to identify the main social, demographic and economic factors operating in India across the major states, which tend to determine the extent and prevalence of child undernutrition in India and pose a major challenge towards achieving our commitment for sustainable development.