To improve the efficacy of measures for parasitic diseases prevention the author recommends, besides routine methods, such as detection and treatment of patients and health educational activities, preventive and current sanitary parasitological survey of environmental objects to be carried out on a wider scale. Parasitologic indexes and their quantitative criteria are presented, as are the basic sanitary and administrative documents which should be the guidelines for parasitologists, sanitary physicians, and epidemiologists in preventive and current sanitary surveillance of environmental objects at foci of parasitic diseases.