Background: Preterm labor is a difficult problem that affects perinatal morbidity and mortality globally. Incidence of premature birth worldwide is 6-11%. Maternal and fetal complications cause preterm birth in 30-40% of causes and the remaining 60-70% are due to subclinical infections or any inflammatory cause like genitourinary infection Aim and Objective: The present study was aimed to study microorganism profile in High Vaginal Swab (HVS) sample of pregnant patients diagnosed as threatened preterm labour. Methodology: In Ghaziabad, Santosh Medical College and Hospital, between the dates of April 19, 2019, and September 30, 2020, a case control observational study was done. Out of the 120 pregnant women enrolled, 60 were assessed to be at risk for preterm delivery and were placed in the case group. The other 60 antenatal women who had reached 37 weeks of gestation but were under 40 weeks along with no pregnancy complications were placed in the control group. Pregnant women were screened in order to collect data based on their medical histories, physical examinations, and laboratory results. Result: Per speculum examination revealed that in the control group only 30% patients had abnormal discharge where as in case group 78.3% patients had abnormal discharge. There was statistically significant (p=0.0001) difference in per speculum examination between cases and controls. Conclusion: In conclusion, Gardnerella vaginalis has been identified as the most common isolate among the pathogens from HVS. Multi drug resistance in isolates indicates the importance of early culture and sensitivity for deciding empirical antibiotics in such patients, if they develop post natal uterine infections.