Aim. Detection of bacteriocins and phages in pathogenic bacteria of Burkholderia genus and study of their specificity range. Materials and methods. Sixty strains of B. pseudomallei, 11 strains of B. mallei , 18 strains of B.cepacia, 5 strains of B.thailandensis, and 3 strains of B.gladioli were used in the study. The agar-overlay method was used to determine bacteriocin activity. For the accumulation of bacteriocins, strains-producers were grown on nutrient broth, inactivated by chloroform and an aqueous phase was spread on the culture surface of indicator strains cultivated on semisolid agar. Phages were isolated with Gratia agar method. Microscopy of phage particles was performed using the electron microscope JEM-100 SX by instrumental magnification 50,000—60,000. Results . It was shown that all studied clinical and collection strains of pathogenic Burkholderia — B.pseudomallei , B.cepacia , B.thailandensis , B.gladioli (total: 97 strains) produced bacteriocins and bacteriophages. The range of their inhibiting activity includes both strains of the same species and heterologous Burkholderia , including B.mallei , which does not have neither bacteriocins nor phages. For the first time presence of bacteriocins in B.pseudomallei strains were detected. Phage B.cepacia B623 effectively lysing B.mallei and not reproducing on B.pseudomallei cultures was identified which is suitable for differentiation of these two species. High sensitivity to the phages of heterologous Burkholderia has been established for B.thailandensis . Set of strains of the latter species allows to detect phagoproduction in virtually all lysogenic cultures of studied Burkholderia spe- cies. Conclusion . Pathogenic Burkholderia being inhabitants of the environment ( B.pseudomallei , B.cepacia , B.thailandensis , B.gladioli ) possess an- tagonistic factors that were lost in the process of evolution in strictly pathogenic B.mallei species.