During the floristic research of different habitat types of Plešivica hills, the floristic composition has shown a great number of medicinal and poisonous plants with 186 taxa that belonged to 52 families. The most dominant families were Asteraceae, Fabaceae, Lamiaceae and Rosaceae. An interesting fact to be pointed out is a large number of plant species that are at the same time poisonous and medicinal. The difference between them is in plant organs or dosage. The highest number of species was noted on ruderal habitats such as roadsides, paths and hedges (137 species), sides of the ditches (94 species), vineyards (72 species), plough-fields (63 species), gardens (54 species) and meadows (48 species).