Fifty-two virus isolates from 13 distinct potyvirus species infecting crops in Vietnam were identified and the 3' region of each genome was sequenced. The viruses were: bean common mosaic virus (BCMV), potato virus Y (PVY), sugarcane mosaic virus (SCMV), sorghum mosaic virus (SrMV), chilli veinal mottle virus (ChiVMV), zucchini yellow mosaic virus (ZYMV), leek yellow stripe virus (LYMV), shallot yellow stripe virus (SYSV), onion yellow dwarf virus (OYDV), turnip mosaic virus (TuMV), dasheen mosaic virus (DsMV), sweet potato feathery mottle virus (SPFMV) and a novel potyvirus infecting chilli, tentatively named chilli ringspot virus (ChiRSV). With the exception of BCMV and PVY, this is first report of these viruses in Vietnam. Further, rabbit bell (Crotalaria anagyroides) and typhonia (Typhonium trilobatum) were identified as new natural hosts of the peanut stunt virus (PStV) strain of BCMV and of DsMV, respectively. Sequence and phylogenetic analyses of the entire CP-coding region revealed considerable variability in BCMV, SCMV, PVY, ZYMV and DsMV.