Partial nucleotide sequences of selected isolates of bean common mosaic virus (BCMV) and bean common mosaic necrosis virus (BCMNV) were determined. Based on these sequences and previously published sequence data, a reverse transcription, polymerase chain reaction (RT-PCR) in combination with restriction endonuclease analyses, was developed for molecular detection of BCMV, BCMNV and some viral pathogroups (PG). Specific detection of the two viruses was accomplished by constructing two virus-specific primer pairs that amplified a PCR product specific for each virus. By application of RT-PCR, four BCMV-PG-V isolates were differentiated from isolates of BCMV pathogroups I, II, IV and VII. Distinction of two BCMNV pathogroups (PG-III and PG-VI) was achieved by restriction enzyme XbaI digestion of BCMNV PCR products. However, no combination of tested restriction enzymes distinguished all five recognized BCMV pathogroups. A primer pair Dts/Uny15 proved to be specific for BCMV pathogroup PG-V. Thus, by a combination of RT-PCR and restriction enzyme analyses, it was possible to differentiate both viruses, two pathogroups of BCMNV, and one pathogroup of BCMV from the others.