The aim of the publication is to present data on quantity and quality changes in the size and structure of population, as well as data on: marriages, separations, divorces, births, deaths and population migrations, which give the opportunity to diagnose the demographic situation of Mazowieckie voivodship in 2017. Moreover, the data allow for analysing different areas of socio-economic life, e.g. data on population by educational and economic age groups enable to determine influence of demographic factor on future of educational system, labour market, and pension benefits.