Forty-seven actinomyces strains were isolated from Antarctic soils - nineteen of them showed antagonistic activity against Gram-positive and Gram-negative bacteria. Six of the strains possessed a broad spectrum of antibacterial activity. Results obtained from the physiological and biochemical analyses including determination of 39 characteristics proved that two of the strains (23 and 29) were similar whereas all the rest differed among each other. Morphological studies indicated that the strains belonged to the genera Streptomyces , Actinomadura and Kitasatosporia . Antibacterial activity of three actinomycetes strains (designed as 29, 30 and 47) was confirmed in batch culture. They were active against clinical isolates from the species Staphylococcus aureus and Streptococcus pneumoniae. The three strains also showed antibacterial activity against the phytopathogenic bacteria Xanthomonas axonopodis pv. glycines, X. vesicatoria, X. axonopodis pv. phaseoli, Pseudomonas syringae pv. tomato and Clavibacter michiganensis , for which no biological means for control, had been developed yet. The broadest spectrum of antibacterial action had the strain 29. The antibacterial compounds produced by these strains probably possessed non-polar structure and consisted of several active components.