Objective of research: Parasitic diseases of which helminthoses are the most dangerous, lead to decrease in livestock numbers, milk and meat production. Therefore, the important task is to develop highly effective broad-spectrum anthelmintics, optimal doses of their application and schedules for dehelmintization taking into account epizootological features of different helminthoses. Materials and methods: Research was carried out at livestock farms of Bagrationovsky, Gvardeysky, Guryevsky, Zelenogradsky, Nesterovsky, Krasnoznamensky, Slavsky, Gusevsky, Nemansky, Prabdinsky, Polessky, Ozersky, Chernyakhovsky districts of the Kaliningrad region. Some jobs were conducted at the Department of Zootechnics of Kaliningrad State Technical University. 680 cattle and 370 sheep heads were investigated. Results and discussion: Monieziasis is spread in all districts of the Kaliningrad region, and causes significant economic damage to livestock. In the Kaliningrad region located in the area of over-moistening, oribatid mites appear on the soil surface in the first decade of April, then the increase in mite numbers is observed until July-August. At infestation of animals at the end of the pasture period, growth and development of helminths is slower than in spring and summer seasons. Preventive (pre-imaginal) dehelmintizations and efficient use of pastures are leading measures for the prevention of monieziasis in ruminants.