The molecular methods currently used in the classification and identification of bifidobacteria are reviewed. The sequencing of the 16S rRNA gene and some other genes considered to be phylogenetic markers is a universal and effective approach for taxonomic characterization of members of the genus Bifidobacterium and to reliable identification of new isolates. Various techniques of obtaining DNA fingerprints (PFGE, RAPD, rep-PCR) are widely used for solving particular problems in identifying bifidobacteria. Bacteria of the genus Bifidobacterium are important organisms in biotechnology and medicine. The research in the field of molecular systematics of bifidobacteria provides a basis not only for the solution of taxonomic problems, but also for monitoring of individual species in the environment and for more detailed study of the genetics and ecology of this group of microorganisms.