Plum pox potyvirus (PPV) was identified in six cultivars of sour cherry in the collection orchard of the Moldavian Horticultural Research Institute. Study of biological properties of the sour cherry isolate in herbaceous indicators showed its similarity or identity with the PPV isolate of Van Oosten and a significant difference from isolates widespread in Moldova. A purified viral preparation was used to develop antiserum with a working titre of 1:1024. Comparative serological examination of the sour cherry and conventional plum PPV isolates using ELISA, ISEM and SDS‐PAGE of the protein capsid could not differentiate these isolates. The sour cherry isolate was transferred to plum resulting in weak but distinctive PPV symptoms in susceptible cv. Sopernitsa.