To analyze the aerobic bacteria isolated from endotracheal secretions of ventilated patients and to evaluate the antibiotic sensitivity pattern and Multi drug resistance of those isolates, present study was conducted in M.D.M. Hospital, Dr. S. N. Medical College, Jodhpur, and Rajasthan, India. Endotracheal secretions received during the study period from Jan 2016 to April 2016 were processed and 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 and tracheotomised patients was recorded. A total of 160 Endotracheal isolates was processed and 114(71.25) of the aspirates was showing growth. The most frequently isolated pathogens were Klebsiella sp.(37.7%), Pseudomonas(18.4%), Esch. coli(15.7) and Acinetobacter sp.(10.5%) followed by Citrobactor sp., Staph. aureus, Proteus sp.. All the organisms more or less showed both sensitive and resistance pattern but Acinetobacter sp was resistant to all the antibiotics except the antibiotic imepenem and ciprofloxacin. This study presents the most common microorganisms colonized and their antibiotic resistance pattern. The variability of flora and the potential need to adjust antibiotic coverage based on culture data suggest that surveillance tracheal aspirates are important during exacerbations