Background: Chronic obstructive pulmonary disease (COPD) is a major cause of morbidity and mortality across the globe. The neutrophil to lymphocyte ratio, which represents the innate and adaptive immune systems, respectively, is known as the neutrophil to lymphocyte ratio (NLR). Hence; the present study was conducted for evaluating the potential role of Neutrophil to lymphocyte ratio (NLR) in patients with Chronic obstructive pulmonary disease (COPD). Materials & methods: 50 patients with Chronic obstructive pulmonary disease (COPD) and 50 patients with acute exacerbation of COPD, who are admitted in MMIMSR, Mullana. Detailed demographic (age, sex, weight), clinical (comorbidities, duration of treatment, days of stay in the hospital, mortality, concomitant antibiotic therapy), laboratory investigations (CBC, Peripheral smear study, Renal function tests, Liver function tests, FBS, PPBS, Serum Vitamin B12 assay) data from each patient was recorded.Results: There was a significant increase in absolute neutrophil count and decrease in absolute lymphocyte count in AECOPD patients in comparison to COPD patients. Mean neutrophil to lymphocyte ratio among the COPD patients was found to be significantly lower in comparison to patients with AECOPD. An NLR of 3.1 was considered the optimal cut-off value with maximal sensitivity and specificity for respiratory hospitalization following ROC curve analysis. The sensitivity and specificity were 68.3 % and 66.4%, respectively. Conclusion: Elevated NLR can be used as a marker in the determination of increased inflammation in acutely exacerbated COPD. NLR could be beneficial for the early detection of potential acute exacerbations in patients with COPD who have normal levels of traditional markers.