We determined a high antibacterial effect of ethanol extracts of four species of gymnosperms (Juniperus sabina, Chamaecyparis lawsoniana, Pseudotsuga menziesii and Cephalotaxus harringtonia) against 23 strains of bacteria of families Enterobacteriaceae (Escherichia coli, Enterococcus faecalis, Salmonella typhimurium, S. adobraco, Proteus vulgaris, P. mirabilis, Serratia marcescens, Klebsiella pneumoniae), Staphylococcaceae (Staphylococcus aureus, S. epidermidis), Yersiniaceae (Yersinia enterocolitica), Bacillaceae (Bacillus subtilis, B. cereus), Listeriaceae (Listeria ivanovi, L. іnnocua, L. monocytogenes), Corynebacteriaceae (Corynebacterium xerosis), Campylobacteraceae (Campylobacter jejuni), Nocardiaceae (Rhodococcus equi), Pseudomonadaceae (Pseudomonas аeruginosa) and one strain of fungi of the Saccharomycetaceae family (Candida albicans). The experiment in vitro revealed zone of inhibition of growth of colonies, measuring over 8 mm, produced by ethanol extracts from J. sabina against seven species of bacteria (S. aureus, B. subtilis, B. cereus, L. іnnocua, C. xerosis, Rh. equi and P. аeruginosa), Ch. lawsoniana – against five species (E. coli, B. subtilis, L. іnnocua and Rh. equi), P. menziesii –two species (Rh. equi and P. mirabilis), C. harringtonia – ten species of microorganisms (E. coli, S. aureus, S. epidermidis, L. ivanovi, L. monocytogenes, C. xerosis, C. jejuni, P. vulgaris, S. marcescens and C. albicans). As a result of the research, the most promising plants for further in vivo study of antibacterial activity were C. harringtonia and J. sabina.