During the 1982/83 and 1983/84 seasons, bean varieties (Orfeo-INIA, Blanco-INIA and TórtolaINIA) that were resistant to the Bean Yellow Mosaie Virus (BYMV). showed symptoms of infection. These symptoms were mosaic, leaf deformation and sometimes, top necrosis. The isolated virus was identified as a new strain of BYMV, which infected a group of species and bean varieties inmune to the "severe strain" of BYMV, present in Chile. This determination was based on symptomatology, transmission.by mechanical means, and byaphids, in a non persistent form, lack of transmission by seeds, physical properties, morphology and size of the virus particles.