Chronic obstructive pulmonary disease(COPD)is a slowly progressive chronic disorder.It is the fourth leading cause of death worldwide.Some patients experience acute exacerbations due to various aetiologies of which about 40-60% are bacterial in origin.Production of beta lactamases and extended spectrum of beta lactamase enzymes by bacteria lead to treatment failure and it is a great economic burden to the patient and the health care system. The work undertaken was able to enumerate the causative bacterial pathogens in acute exacerbations of COPD, their antibiotic sensitivity patterns and resistant mechanisms. Thus this study will provide useful information for the empirical management of COPD patients with acute exacerbations and will help in the development of an antibiotic policy for this alarming illness as haphazard and irrational antibiotic treatment for extended periods will enhance the emergence of antibiotic resistance.