The PCR offers the possibility of specific and very sensitive detection and/or identification of Cl. m. subsp. michiganensis in seeds. The described PCR method for identification of this pathogen is very fast (one day) and economical, because of the very small volume (10 μI) of the PCR reaction mixture. The method based on amplification of the bacterial plasmid DNA fragment may be very useful in routine identification of Cl. m. subsp. michiganensis from all other bacteria isolated from tomato seeds and may be an alternative tool in diagnostics, especially for the quarantine services.