Aim: To analyse the changing spectrum of aerobic bacteria isolated from endotracheal secretions of Mechanically ventilated patients andto evaluate the antibiotic sensitivity pattern __ampersandsignamp; Multi drug resistance of those isolates Materials and Methods: Endotracheal secretions received during the study period from Oct 2010 to Dec 2012 were processed __ampersandsignamp; all the pathogenic isolates were identified as per the standard guideline. Antibiotic sensitivity was performed for the identified pathogens according to CLSI standards. Clinical condition of the ventilated __ampersandsignamp; tracheotomised patients were recorded. Results: A total of 95 Endotracheal isolates were processed and 73 % of the aspirates were showing growth. The incidence of VAP was 33.3% and most frequently isolated pathogens were Klebsiella spp(36%), Pseudomonas(17%) __ampersandsignamp;Acinetobacter spp(18%).Multidrug resistance was observed in 53% of Klebsiella spp, 26% in Pseudomonas and 56% in Acinetobacter spp.Most of the patients (33%)were ventilated for Trauma and hence most of the patients had prolonged hospital stay __ampersandsignndash;average time being 25 days. Conclusion: In this study we observed that there was a gradual shift in the isolated aerobic bacterial profile. Initially in 2011 the frequent pathogen was Klebsiella spp(41%) __ampersandsignamp;Pseudomonas spp(18%) when Acinetobacter was 10% . In 2012 Acinetobacter was found to be the most prevalent pathogen (30%) and klebsiella spp prevalence reduced to 28%. Multidrug resistant was also observed among the isolated pathogens. Prolonged hospital stay for trauma has resulted in multidrug resistance and change in bacterial profile. Empirical antibiotic therapy was recommended based on the antibiogram of the most prevalent pathogen in ICU.