Among seed-transmitted cereal viruses the most important is Barley stripe mosaic virus (BSMV), infecting barley. Investigations on the occurrence of BSMV in Poland have been carried out in the Institute of Plant Protection in Poznań since 2000. The studies aimed at the evaluation of the BSMV distribution in plant material, the rate of its seed transmission in different barley cultivars and the assessment of the effect of barley infection on the yield. The potential risk of BSMV occurrence for barley crops was discussed. The rate of infection by two seed-transmitted viruses, Maize dwarf mosaic virus (MDMV) and Sugarcane mosaic virus (SCMV), in Poland was investigated in view of the risk assessment.