Ornamental plants are attacked by a significant number of plant parasitic nematodes, some of which may be considered as pests of economic importance. During the last two years numerous samples have been collected from seven ornamental nurseries in South Bulgaria for detection of phytoparasitic nematodes. As a result of the extractions made from plant materials and substrate samples, plant parasitic nematodes belonging to eight generawere detected. The highest population density of the parasites was found in petunia (Petunia sp.), chrysanthemum (Chrysanthemum sp.), and begonias (Begonia sp.). An experiment was conducted to determine the pathogenic effect of one species of the genus Meloidogyne Goeldi (root-knot nematodes) in petunia. The most negative impact was observed when the petunia plants had been infected with 600 second stage juveniles (J2) of Meloidogyne incognita. In that variant the reported gall index on the plant roots was the highest – 5.4 at relatively low gall numbers (84.4) and number of egg masses (68.4) for the root system.