In the years 1997-1999, studies on the intensity of the slug Arion lusitanicus occurring in different microhabitats were carried out on the territory of Podkarpackie province. Observations were performed in the environments of vegetable gardens, arable fields and non-crop areas. The intensity of the slug occurrence varied greatly in arable crops of different plant species and in other microhabitats. Vegetable crops and areas adjacent to them were inhabited by the slug most numerously. Considerably less slugs occurred in agricultural plant crops.