The species Erwinia carotovora (Pectobacterium carotovorum) consists of several subspecies of gram-negative, non-spore-forming, peritrichous, fermentative rod-shaped bacteria and belongs to the Enterobacteriaceae family. E. carotovora causes highest lasses of agricultural crops, vegetables and fruits of which the potato is economically most important. The prevention and control strategies for this dangerous bacterial pathogen is possible only through application of early and efficient detection and identification methods. Biochemical, serological and molecular methods suitable for the diagnosis of the pathogen were described. Application of several methods, including molecular markers, for genetic differentiation of the bacteria belonging to the same species or subspecies was also presented.