We report on abundance and natural infection rates of Fasciola hepatica in Lymnaea truncatula snails from endemic rural areas of the Moscow Region. Field surveys were carried out monthly between May and October 2002, in two cattle farms of the Naro-Fominsk district and two of the Dmitrov district. Snail abundance was maximum in May (189 snails in spring) and minimum in July (5 snails in summer), probably due to more suitable microenvironmental conditions for snail development during spring. The prevalence registered during the studied period was 14.3%, with the highest (12.5%) and lowest (0.5%) estimates in September and May, respectively.