Surveys were carried out in the Czech Republic to type Plum pox virus (PPV) isolates from stone fruit orchards and wild trees. WiId trees (plums and myrobalans) or cultivated plums grown along roads, were found to be the main and primary sources of PPV. From 263 tested plums, 119 were PPV-infected. Virus infected trees were found mainly in central, western and eastern Bohemia and north-western and central Moravia. As far as myrobalan was concerned, PPV was detected in 51 of 132 trees. A total of 12 sour and 45 sweet cherry trees tested negative. Some 254 blackthorns were tested and 36 were infected, mainly in lowlands of central, western and eastern Bohemia, central and southern Moravia, i.e. in plum and myrobalan areas with high incidence of PPV. PPV-D was the main strain of the virus in the Czech Republic. PPV-M was found only in a few trees of peach, plums and one damson tree.