This paper presents population forecasts for China and India till 2100. The rise in sex ratios at birth in these countries has been observed to be the longest-running and most pronounced in Asia. The paper is based on different hypotheses on the future evolution of birth masculinity in each of these countries. These hypotheses are derived from an examination of present trends across Asia. The population forecasts allow us to explore the influence of various trajectories of sex ratio at birth on the demographic structures of both countries till 2100. In particular, the specific impact of skewed sex ratios on the adult population in which gender imbalances may translate into a major marriage squeeze in the future will be examined. [ABSTRACT FROM AUTHOR]