The paper deals with occurrence of plasmids in P. syringae strains belonging to seventeen pathovars: the strains were isolated in the USSR and other countries. One to four different plasmids having molecular weights of 20 to 90 Md have been found in various strains of the following twelve pathovars: holci, cerasi, aptata, tabaci, populi, pisi, lupini syringae, lachrymans, phaseolicola, glycinea, atrofaciens. Both virulent and avirulent P. syringae strains appear to carry such plasmids. Plasmids of incompatibility group P-2 do not occur in the strains studied.