Three approaches to identification of powdery mildew resistance genes in wheat - comparison of reaction patterns based on host-pathogen interaction, chromosomal location of resistance genes by means of genetic and cytogenetic assessment, and molecular identification - are reviewed in this paper. The paper covers publications published mostly in the nineties. The derivation and current status of twenty-five Pm genes in wheat are presented. RAPD, RFLP and STS markers closely linked to some specific resistance genes, from recent reports, are listed. These can be useful to phytopathologists and breeders who are interested in the practical application of wheat powdery mildew resistance genes.