Soft-bodied is the intermediate host of helminthiases, in the body of which several development stages of larval forms of helminths occur. There is the highest population density of mollusks in the areas of ruminant grazing, which leads to mass infection of animals with trematodes. To destroy the intermediate host of helminths in agricultural production, molluscicidal remedies of synthetic and plant origin are used. The work aimed to determine the molluscicidal effectiveness of a plant remedy based on Silene Latifolia in conditions of natural pastures. The material for work was the green mass of the plant S. Latifolia obtained in the warm season from roots, leaves, stems, flowers, and seeds. By grinding this plant, a powder with a particle size of 1-3 mm was obtained. Then, the powder was extracted with ethyl alcohol. The obtained product (concentrate) was an amorphous gel-like mass of dark green color with a specific smell and well soluble in water. Fieldwork in natural pastures was carried out on 5 biotopes with an area of 4-25 m2. Three species of gastropods were recorded from freshwater mollusks in the biotopes: Planorbis planorbis, Planorbarius corneus, Physa fontinalis, Lymnaea truncatula, and L. palustris. The results of experiments conducted in the conditions of pastures indicate a high molluscicidal activity of the studied plant agent on pond fish, intermediate hosts of trematodes pathogens. The effectiveness of the developed molluscicide on gastropods, when treated with a working solution (10.0 g/l) is from 98.1 to 100%.