Studies on nocturnal Lepidoptera were carried out on the Laukėnai raised bog and the adjacent wet forest in 2001. Species composition and abundance were evaluated and compared. The species richness was much higher in the forest than at the bog. The core of each lepidopteran community was composed of 22 species with an abundance of higher than 1.0% of the total catch. Tyrphophilous Hypenodes humidalis (22.0% of all individuals) and Nola aerugula (13.0%) were the dominant species in the raised bog community, while tyrphoneutral Pelosia muscerda (13.6%) and Eilema griseola (8.3%) were the most abundant species at the forest site. Five tyrphobiotic and nine tyrphophilous species made up 43.4% of the total catch on the bog, and three and seven species, respectively, at the forest site, where they made up 9.2% of all individuals. 59% of lepidopteran species recorded on the bog and 36% at the forest site were represented by less than five individuals. The species compositions of these communities showed a weak similarity. Habitat preferences of the tyrphobiontic and tyrphophilous species and dispersal of some of the species between the habitats are discussed.