The purpose of this study was to assess the results of bacteriological studies in children born prematurely and compare the received data with the detected neonatal morbidity. Methods and Results: Our study included 227 pregnant women at gestational age of 28-36 weeks 6 days, and their newborns. Depending on the gestational age, they were divided into 3 groups. Group 1 included 73 women at gestational age of 28-30 weeks 6 days; Group 2 included 81 women at gestational age of 31-33 weeks 6 days, Group 3 included 73 women at gestational age of 34-36 weeks 6 days. All women underwent an assessment of vaginal microcenosis and the quantitative and qualitative composition of the biotope of the cervical discharge; the newborns underwent bacteriological examination of the auricle, pharynx and anus. Analysis of the results of bacteriological studies shows a significant growth of microorganisms in newborns from mothers of Group 1. The analysis of morbidity among premature infants showed that in each group there were 2 or 3 diseases, mainly of an infectious nature. The main proportion of morbidity (congenital pneumonia and infections of the perinatal period, diseases of the urinary system, neonatal jaundice of premature infants and cerebral ischemia) among newborns was found in Group 1, compared with Groups 2 and 3. The analysis of the results obtained showed that the low birth weight in preterm labor correlated with the growth of Staphylococcus epidermidis in the throat of newborns. Neonatal jaundice of premature newborns was characterized by 100% detection of Staphylococcus epidermidis and Serratia odorifera in the anus swabs, and Staphylococcus epidermidis in swabs from the pharynx and ear. Congenital pneumonia positively correlated with the growth of Staphylococcus epidermidis, E. coli, Candida spp, Enterococcus faecalis in the throat swab. The deceased children had a co-infection. Conclusion: Our study identified the main microorganisms affecting both perinatal morbidity and neonatal mortality: Staphylococcus epidermidis, Enterococcus faecalis, E. coli, Candida spp. It is necessary to note the frequent identification of E. coli strains resistant to the main antibacterial drugs. © 2020, International Medical Research and Development Corporation. All rights reserved.