The karyotypes of two stilt bug speciesMetatropis rufescens(Herrich- Schaeffer) ssp.linneaeWagner andBerytinus minor(Herrich-Schaeffer) (Heteroptera, Berytidae) were reinvestigated by an improved method to analyze chromosomes and their meiotic behaviour. The chromosome formula 2n(♂) = 18 + XY forM. rufescensssp.linneaewas confirmed and a novel chromosome formula forB. minor, 2n(♂) = 42 + X1X2X3Y, was given. This is the first finding of multiple sex chromosome system in this family. Male meiosis is chiasmatic for autosomes. Sex chromosomes undergo post-reductional meiosis. C-banding method revealed heterochromatic bands near one of the telomeres in some but not in all chromosomes inM. rufescensssp.linneae.The present data on chromosomes in the family Berytidae are discussed.