Introduction- Chronic Obstructive Pulmonary Disease is a frequent respiratory disease seen in chronic smokers. These patients occasionally suffer from episodes of exacerbations, characterized by increased breathlessness, cough and sputum. Bacterial infection is one of the common causes of these exacerbations. Objectives- The study aimed at isolating the bacteria responsible for causing these exacerbations and finding their sensitivity to anti-bacterial agents. Methods- The study was conducted in Silchar Medical College and Hospital, Assam in 114 patients of this disease. Expectorated sputum samples were sent for culture and antibiotic sensitivity. Results- 70.2% patients showed bacterial growth in the sputum. Out of these, the following organisms were isolated- Klebsiella pneumonia (46.25%), Staphylococcus aureus (28.75%), Pseudomonas aeruginosa (16.25%), Acinetobacter species (5%) and Streptococcus pneumonia (3.75%). Gram Negative organisms were most sensitive to Imipenem, Meropenem, Piperacillin-Tazobactam. Gram Positive organisms were most sensitive to Vancomycin and Linezolid. Conclusion- Bacterial infection is the frequent cause of exacerbations in Chronic Obstructive Pulmonary Disease. Klebsiella pneumonia is the commonest organism responsible. Keywords: Chronic Obstructive Pulmonary Disease, Exacerbation, Sputum, Bacteria, Anti-Bacterial Agents