This study proposes a well-being index of older adults which integrates five domains, namely, activities of daily living, health status, psychological strength, life accomplishment and social ties, and examines potential socio-demographic, living arrangement, lifestyle and religiosity determinants of well-being. The present study uses micro data of 1255 older adults from the recent pilot survey for the Longitudinal Aging Study in India (LASI) conducted in 2010. The results suggest that normal activities of daily life, health, and social ties decline with advancing age, while life accomplishment remains stable over age. However, when all domains are integrated, well-being tends to fade out with advancing age. While smoking has a deterrent effect on well-being, better economic status, literacy, living in a joint family with spouse, religiosity, and regular physical exercise have a statistically significant positive effect on the well-being of older adults in India. © 2016, Springer Science+Business Media New York.