Background: Oropharyngeal colonization by pathogenic organisms especially in the initial crucial days of ICU admission, is the main cause of predisposition to nosocomial infections. Hence, identifying bacterial flora, in respect to hospitalization will help in further management to prevent morbidity and mortality of these patients. Objective: Determining changes in bacterial flora in oropharynx of patients with nasogastric tube, admitted in ICU. Methods: One year prospective observational study including 40 patients between 18 and 70 years, Group A 20 cases- with nasogastric tube in situ, Group B 20 controls including those without tube. Oropharyngeal swab taken on Day 0 and 7 of ICU admission respectively. Results: There was nearly equal distribution of gender, with 19 females and 21 males, majority in the age group of 35-74 years. Most of patients had no growth on day 0 (35% cases) but as the day of ICU admission progressed, there was increased growth of Gram negative bacteria like Pseudomonas aeruginosa (20%), Klebsiella pneumonia (25%) especially in cases group. Conclusion: The progressive increase of pathogenic organism and the variation to gram negative bacteria further confirmed predispositions to pathogen carriage at these sites and the subsequent risk of infection within the crucial 48 hours. Hence, need for consistent oral cleansing procedures, maintaining good oral hygiene in these prolonged tube-fed patients will help prevention of nosocomial infections.