Plum pox virus (PPV) isolates were collected in Hungary from plum varieties. PCR targeting the 3' genomic region resulted in a shorter PCR product in the case of the B1298 isolate bearing a 135-nucleotide deletion in frame in the N-terminal part of the coat protein (CP). The isolate was aphid-transmissible and the virion diameter was reduced compared to PPV-SK68. Detectability of this isolate by Western blot varied according to the antibody used. Integration of the deleted CP gene into an infectious PPV clone had no effect on infectivity and symptomatology. In competition experiments, B1298 had a considerable advantage in virus accumulation.