The main purpose of the paper was to defi ne the determinants of professional activity of working age population. The professional activity of the investigated population, taking into account selected demographic features, namely gender, age, place of residence, were discussed in the article. The inquiry research was carried out in 2013 on the area of the Wielkopolskie voivodeship on 386 people at production age. In addition to the primary data, the secondary data originating from the Social Security Offi ce and Eurostat were used. The conducted research proves that the vast majority of the inquired was professionally active. Among the professionally active, the employed under a contract of employment in full-time employment dominated. Only few of the inquired undertook an additional job. Among women, the main reason for increase of professional activity was obtaining low income from the basic source of income. The investigated women obtained lower incomes than the men.