Bean common mosaic potyvirus (BCMV) and Bean common mosaic necrosis potyvirus (BCMNV) are economically the most important viruses of common bean. They can reduce yield and quality of harvested product. High percentage of seed transmission (up to 83%) is one of the reasons for its distribution worldwide. They represent 7 pathogenicity groups and 10 strains. Pathogenicity groups can be determined by reactions of differential bean cultivars. BCMV and BCMNV can be differentiated on serological and molecular level but all strains cause similar symptoms in bean genotypes lacking resistance genes. The development of different reactions to virus infections depends on virus strain, bean cultivar and temperature. The host resistance genes and virus pathogenicity genes interact in development of different responses of bean plants after infection. Different combinations of dominant and recessive strain unspecific and recessive strain specific resistance genes confer more stable resistance to wider spectrum of virus strains. The causal viruses, interactions of host resistance and virus pathogenicity genes, in vivo recombinations of both viruses and methods for selecting the desired host genotype are reviewed.