PURPOSE: The purpose of this study was to compare the efficacy of 7-day and 14-day courses of oral prednisolone treatment in patients with acute exacerbation of COPD with FEV1<50% predicted. METHODS: It was a prospective randomized, single blind study in a tertiary care center, the study patients were included and randomized into two groups: 7-day group received oral prednisolone 30 mg./day for 7 days, and 14-day group was administered the same dosage of oral prednisolone for 14 days. There was no significant difference between the groups for age, smoking pack years, symptoms of COPD in years, no. of previous exacerbations, blood eosinophilia, baseline FEV1,and FVC levels. One patient from 7-day group developed pneumothorax and one from 14-day group died of acute Myocardial Infarction. RESULTS: Both groups showed significant improvements of FEV1 and FVC on D-1, D-3, D-5, D-7, D-10 and Day-14 from the baseline (7-day group, p = 0.0001, 0.0001, 0.008, 0.009, 0.008, 0.011and 14-day group, p = 0.000, 0.000, 0.000, 0.000, 0.000, 0.000.) and the improvement of FVC is also significant in both the groups, but there was no significant difference of improvement between the two groups on day-7 and day-14 (p = 0.100, 0.079). There was also significant improvement of symptom score from baseline on day-7 and day-14, but no significant difference of improvement between two groups. CONCLUSION: In acute exacerbation of COPD there is no difference between 7-day and 14-day courses of treatment with oral prednisolone. The peak of FEV1 and FVC in 7-day group on day-10 where corticosteroid was already stopped on day-7, (peak in 14-day group was on day-7) might be due to some other factor/factors responsible which would be cleared by further study. CLINICAL IMPLICATIONS: There was no difference between 7-day and 14-day courses of prednisolone treatment, so, 7-day might be the shortest effective course of steroid treatment in Acute exacerbation of COPD to avoid the burden of cost and side effects.