Diseases of newborn calves with acute intestinal infections occupy one of dominant positions in in-fectious pathology of bacterial etiology. The aim of the study was the investigation of antibiotic suscep-tibility and antibiotic resistance of pathogenic and conditionally pathogenic microflora of the intestine of newborn calves with clinical signs of intestinal infection. 32 tests of biological material from new-born calves with clinical signs of intestinal frustra-tion were subjected to bacteriological research. Morphological and cultural properties of the isolates emitted from biomaterial studied by crops on usual and special environments with subsequent incuba-tion in the thermostat at the temperature of 37 °C during 18-24 hours. Microorganisms’ identification was carried out with use of "Determinant of bacteria of Berdzhi". The main causative agents of intestinal infections of newborn calves were the following representatives of Enterobacteriaceae family: 5.4 % - Proteus mirabilis; 19 - Escherichia coli; 9.5 - Proteus vulgaris, Enterobacter aerogenes; 4.8 % - Yersinia enterocolitica and Klebsiella pneumonia. Polyresistance to antibacterial prepara-tions cultures was shown by Proteus vulgaris, Enterobacter aerogenes and Klebsiella pneumonia, moderate resistance - by Escherichia coli, Proteus mirabilis and Yersinia enterocolitica. The cultures of opportunistic Escherichia coli were resistant to erythromycin (95.2 %), tetracycline and penicillin (90.5 %), canamycin (85.7 %), ampicillin (76.2 %), streptomycin and gentamicin (71.4 %). Most cul-tures of Escherichia coli showed sensitivity to polymyxin (85.7 %), ciprofloxacin and enrofloxacin (71.4 %), less to levomycetin - 66.7 %. 71.4 % of opportunistic strains of Escherichia coli possess polyresistance. Monoresistant strains of Enteroba-cteriaceae family representatives were not re-vealed.