Arion lusitanicus Mabille (= A. vulgaris Moquin-Tandon) causes significant crop damage in some parts of Poland. In the course of research into alternative methods of limiting the damage caused by A. lusitanicus to crop plants, no-choice tests were carried out on the palatability and consumption of 95 species of herbaceous plants and oilseed rape. In controlled laboratory conditions, over six consecutive days, the damage to the plants caused by the slug was observed (in the 2–3 leaf phase). For each tested plant species, a palatability index (P.I.) and a consumption index (C.I.) were determined. As a result of the observations the slugs’ feeding behaviour was described, palatable and unpalatable plants were distinguished, and the degree of acceptance of those plants by the slug was determined. A. lusitanicus showed differentiated preferences in respect of various plant species. Approximately 23% were unpalatable plants, and 48% low-palatability plants. Unpalatable plants included such species as Impatiens roylei, Geranium robertianum, Saponania officinalis, Glechoma hederacea, Epilobium palustre and Geum urbanum. 26% of the tested species are palatable to the slug. These include Artemisia dra¬cunculus, Tripleurospermum inodorum, Datura stramonium, Lamium amplexicaule, Myosotis arvensis, Satureja hortensis and Conium maculatum. The remaining two species (Ocimum basilicum, Trifolium repens) have palatability equal to that of the control plant Brassica napus. It was noticed that the level of acceptance of particular plant species by A. lusitanicus was not affected by the plants’ life cycle and their family membership. It was found that there was highly significant differentiation in slugs’ feeding behaviour depending on the plant species.