For several decades now Europe has undergone population ageing. Within the coming half a century or so that process will be intensified, which will result in a fundamental shift in the relationship between the youth and the elderly. Numbers of young people which are supposed to replace persons in reproductive (and working) age will be declining whereas numbers of old people, those who require support and care will be growing. In other words, an increasing demand related to those needs that will result from the ageing of population will be met by decreasing demographic resources, which – by present standards – serve the satisfaction of such demand. Poland belongs to countries where that change will be particularly drastic. By the year 2060 from one of the youngest populations in the European Union it will become the oldest one. I argue that this process – which I consider the principal demographic challenge Europe is facing – is unavoidable, and it will become irreversible within several decades. Despite illusions, a response to ensuing social and economic challenges cannot be found in the demographic change itself, especially the one to be accomplished by means of population policies (including migration policy). The effective solutions are to be sought in other spheres than the demographic one.