This article is written to verify the hypothesis which states that the share of land used by farms within the surface of cities and their scope of production usage are determined by the mechanism of land rents. It can be noted that in big cities (above 500 thousands of inhabitants) and in cities with a concentration of companies from non-agricultural sector, the share of agricultural lands is above 8.5 and 5.1 percentage points lower than in the researched city population. It should also be mentioned that in these units above 35% of agricultural lands are not used agriculturally, whereas in Polish cities, on average, this proportion amounts up to about 28%. Upmost importance to the use of lands in cities is also attached to speculative actions and public intervention, which are prevalent in big cities and cities with a large number of companies from non-agricultural sectors.