Karyotypic details were studied in males of six beetle species from three families, viz. Tenebrionidae: Dailognatha pumila Bdy. (2n = 20, n(male) = 9 + Xy(p)), Pachyscelis musiva Ménétr. (2n = 18, n(male) = 8 + Xy(p)), Pimelia capito Kryn. (2n = 18, n(male) = 8 + Xy(p)); Cerambycidae: Agapanthia walteri Reitt. (2n = 20, n(male) = 9+Xy(p)), Agapanthia korostelevi Danilevsky (2n = 20, n(male) = 9 + Xy(p)); Curculionidae: Phyllobius caucasicus Stierl. (2n = 22, n(male) = 10 + Xy(p)). The chromosome number and sex determining system of all beetle species are described for the first time. Evolutionary trends in karyotypes of the studied beetle groups are briefly discussed.