The aim of this study was genetic characteristics of serotype O of foot-and-mouth disease virus isolates, selected from the national collection and originating from the FMD outbreaks, which were reported in Poland in 1959-67. The nucleotide sequences of the region coding for VP1 protein, obtained by amplification and sequencing, were analysed. The genetic similarity of most local isolates indicates a common source of their origin. The comparison of the sequences of local isolates with those available from data bank demonstrates lack of their closer relationship, except one isolate, which is related to the 01Campos/Brazil/71.