China and India account for nearly 36% of the world’s population. The two countries are expected to see an unprecedented, accelerated rate in elderly populations, a shift that has already begun and will continue in the years ahead as life expectancy continues to increase and fertility to decrease or remain below replacement levels. Examining demographic changes can offer a unique opportunity to enrich the theoretical and empirical understanding of the economic aspects of population ageing. This special issue of the Journal of the Economics of Ageing, coedited by David E. Bloom, the Clarence James Gamble Professor of Economics and Demography at Harvard University, and Karen Eggleston, a Center Fellow at the Shorenstein Asia-Pacific Research Center at Stanford University, is a diverse collection of micro- and macro-economic research on ageing in China and India. This introduction, co-written by Bloom and Eggleston, provides background context to demographic trends in China and India, connections between demographic and economic changes and possible behavioral and policy responses. The introduction also gives a preview of the main contributions of the 10 articles featured in the special issue, which cover topics such as the impact of non-communicable diseases in China and India, how parents’ expectations of co-residence with their children affects educational outcomes, and the prevention of cognitive decline in China.