The sand dune and oak forest near Sládkovičovo represents the northern occurrence of such biotopes in Slovakia. In these biotopes, we processed the fauna of bugs (Heteroptera). We obtained a total of 171 species using several methods. We found 151 species of bugs on the sand dune and 101 in the forest. The sand biotope is characterized by the following species: Prostemma guttula, Prostemma sanguineum, Geocoris ater, Geocoris erythrocephalus, Neides tipularius, Odontoscelis lineol, Cydnus aterrimus, Thyreocoris scarabaeoides, Psacasta exanthematica, Psacasta neglecta, Melanocoryphus albomaculatus.