A review of the Polish species of Cydnidae is presented. The data on Ochetostethus nanus from Poland should be referred to O. opacus. Canthophorus impressus is recorded for the first time from Poland. Following species are recorded: (Cydninae): Aethus flavicornis (F.), A. nigritus (F.), Cydnus aterrimus (Forst.), (Sehirinae): Legnotus limbosus (Geoffr.) [= Pentatoma (Cydnus) notatum Schilling, 1844], L. picipes (Fall.), Sehirus luctuosus Muls. et Rey [= S. morio auct.], S. morio (L.) [= S. affinis auct.], Tritomegas bicolor (L.), T. sexmaculatus (Ramb.), Canthophorus dubius (Scop.) [= albomarginellus], C. impressus (Horv.), Adomerus biguttatus (L.), O. opacus (Scholtz) [= nanus auct.]. Host plants and notes on biology are also presented