In central Europe, winter barley is infected by a broader spectrum of pathogens than spring barley. However, the dominant disease on susceptible cultivars is powdery mildew. The objective of this contribution was to postulate resistance genes in cultivars registered in the Czech Republic and Slovakia from 1993 to 2010 using a set of 40 isolates of the barley powdery mildew pathogen. Seedlings of 42 European cultivars were tested, and 15 known resistance genes were postulated namely, Mla6, Mla7, Mla12, Mla13, MlaRu4, Mlg, Mlh, MlLa, Mlra, Ml(Ch), Ml(Dr2), Ml(IM9), Ml(Lo), Ml (Ru2) and Ml(St). Two unknown resistances were detected, one in cultivars Gilberta, Mirko and Polana, and another in Ricus. Three cultivars (Campanile, Carrero and Mirko) were heterogeneous for mildew response. The most frequent genes were Mlra and Mlh, which were found in 25 and 14 cultivars, respectively. Genes located at the Mla locus were present in 14 cultivars; 11 of these cultivars carried Mla6. No resistance gene was detected in Hanna. Previously unknown resistances will be further characterized.