ABSTRACT Chronic obstructive pulmonary disease (COPD), a common respiratory disorder has high morbidity and mortality. The frequency and severity of disease exacerbation are the most important factors in determining the overall prognosis of COPD. Recent studies have shown that bacteria play an important role in the exacerbation of COPD, and up to 50% of exacerbations are caused by bacterial infections. Serum C-reactive protein (CRP), a sensitive biomarker for systemic inflammation and tissue damage, is a good indicator of lower respiratory tract bacterial infections. This study was conducted to evaluate role of CRP in acute exacerbation of COPD (AECOPD), and whether it can guide the clinician to start prescribing appropriate antibiotics rationally and avoid their indiscriminate use. A total of 65 patients were included in this study over a period of 18 months conducted and studied using standard statistical methods. 78.46% patients had raised CRP levels (>6mg/dL). 56.9% of patients had bacterial aetiology for AECOPD, of which more than 50% had positive sputum bacterial culture. Normal CRP was seen in 8.1% patients with bacterial exacerbations against 39.3% patients with nonbacterial exacerbation which was statistically significant (p value 0.006). The mean CRP levels too were significantly higher in bacterial exacerbations group (p value 0.0011). The sensitivity of CRP (> 6 mg/dl) to detect bacterial AECOPD is 91.8% and specificity is 39.2%. CRP may be used as an initial investigation in deciding use of appropriate antibiotics in acute exacerbation of COPD. Keywords: Acute exacerbation of chronic obstructive pulmonary disease, C-reactive protein