The demographic forecast developed by the Central Statistical Office (CSO) assumes a progressive decrease in the population of Poznan, characteristic of all other major cities in Poland. By 2035, the city's population will have reduced to ca. 490 thousand people. This decrease in population will be seen both amongst those in the pre-workingage (16%, after a period of growth in 2010-2021) and the working age (19%). On the other hand, the post-working age population will increase significantly (19%). This forecast, which takes into account the diversity of trends among age groups below 24 years, alongside the general population decline in Poznan, also indicates temporary growth in the population of children and teenagers aged 3 to 6, to 2015, 7 to 12, to 2021 as well as 13 to 15, in 2016-2025, from 16 to 18, in 2019-2028, and from 19 to 24, in 2023-2033. In contrast, according to the forecast of the Central Statistical Office, the situation will be different in the Poznan District, where, until 2035, the population is expected to increase by by half and amount to 480 thousand. As a result, in 2035, the population of the Poznan Agglomeration, including the city of Poznan and the Poznan District, will increase by about 10% and amount to 970 thousand.