The aim of the study was to find out whether carriers of new lethal mutation in SDE2 gene occur in the population of Polish Holstein-Friesian bulls. Eighty seven bulls were included in the analysis. Bulls were selected as having in the pedigree known carrier of SDE2 mutation (bull Mountain USAM000002070579). All bulls were diagnosed by PCR amplification of 524 bp fragment of SDE2 gene followed by digestion of Bcc I restriction enzyme. Heterozygotes (carriers) were confirmed by sequencing. Each new carrier was used to trace another potential carriers among its offspring available in Polish Holstein Bull Repository Database. Among 87 bulls, 50 new SDE2 carriers were found. The study has shown that mutation in SDE2 gene causing early embryo mortality is already transmitted to Polish Holstein-Friesian cattle. The results are sufficient to initiate the screening program to reveal new carriers and to avoid further spreading of SDE2 lethal mutation.