Introduction: COPD, which a disease of increasing public health significance in the world, is presently the fourth leading cause of death. In COPD patients, the increased prevalence of osteoporosis and osteopenia may be an indication of a link among deficiency of Vitamin D and COPD. Aim of the study: To determine the baseline Vitamin D status of patients hospitalized with acute exacerbation of COPD. Material and Methods: The present Prospective observational cohort study was conducted at the Post graduate Department of Medicine among 70 patients for one year. Blood samples were collected at baseline for Vitamin D levels. Three to five ml blood was collected in serum vial and was kept at room temperature for half an hour. After the incubation, serum was separated by centrifuging the tubes at 2000 rpm for 5 minutes to separate serum. Data analysis was done using SPSS 22.00 for windows; SPSS inc, Chicago, USA. Results: Out of 70 patients, low and normal vitamin D level was found in 68.57% and 31.43%. When vitamin d level was compared according to BMI, FEVI/FVC ratio, no. of exacerbation/year, no. of hospital stays (in days) and mortality, significant difference was found as p<0.05. Conclusion: Hypo-Vitaminosis D was significantly associated with AECOPD. Further investigations are required to define the role of genetic susceptibility and base line vitamin D status in the pathogenesis of acute COPD exacerbations.