The first part of this paper documents the striking changes in population size and structures which have occurred since the beginning of transition, and which have led to a substantial reduction in the child population. It is argued that they have been mainly driven by the drop in birth rates which has characterised the whole region, but which has been most dramatic in the CEE and Western CIS. Some countries in these subregions now rank among those with the lowest levels of fertility in the world, and the shrinking cohorts of children in these countries face the prospect of a growing old-age dependency burden. The second part of the paper discusses recent data on infant and under-five mortality, which are direct measures of child well-being, and of the success of policy measures aimed at improving child survival and development. The paper highlights the marked differences not only in levels, but also in progress in reducing mortality rates across the CEE/CIS.