The aim of this paper was to analyze reasons and a range of changes in agricultural land areas due to allocation them for non-agricultural purposes across a period of 1990-2015 in Poland. This phenomena has not been sufficiently considered till now. Lack of this knowledge does not allow effective reduction of the decline of agricultural land by appropriate legislation and administrative action, especially on urban areas. In Poland, a significant proportion of agricultural land is allocated annually for non-agricultural purposes, which is connected with their permanent withdrawal from agricultural production. The permanent decline in the area of agricultural land in the country has been observed since the beginning of the systemic transformation. The dominant direction of the land withdrawal for non-agricultural purposes is their allocation to housing construction. In 1995 the Law on the protection of agricultural and forest land was introduced. This law includes strengthened economic tools for the protection of agricultural land in the form of mandatory charges for the withdrawal of agricultural land showing the best soil quality. This has led to a significant reduction in agricultural land use withdrawal. However, accelerated regional development following the accession of Poland to the EU and, then, the need to expand technical infrastructure resulted in several amendments to the 1995 Act, significantly weakened the protection of agricultural and forest land. It seems that the land as the unrepeatable good should be strictly covered by more respect and protection than ever before, especially in areas with the highest production value.