Background: Studies have demonstrated that red blood cell distribution width (RDW) is closely associated with the prognosis of patients with chronic obstructive pulmonary disease (COPD). In addition, the dynamic changes in RDW appear to play an important role. Thus, we aimed to investigate the relationship between dynamic changes in RDW and 30- day all-cause readmission of patients with acute exacerbation of COPD (AECOPD). Methods: This is a prospective and observational study was conducted in the Department of Pulmonary Medicine, J J M Medical college, Davangere Patients hospitalized for AECOPD between April 2020 to March 2021 were revised. Clinical and laboratory parameters were noted. Participants were followed to determine the incidence of readmission due to AECOPD, readmission from any cause and composite end point of readmission or death during 60 days after discharge. Result: Maximum patients in both groups were found in>60 years age group. The mean age in AECOPD group was 66.75±10.35 years and in Stable COPD was 65.31±11.25 years. Both groups were comparable. Maximum patients in both groups were presented with cough and breathlessness. Maximum patients in AECOPD group was from GOLD stage 4 and in stable COPD was also from GOLD stage 4. The difference in both group was foundstatically significant. Mean FEV1% significantly lower in AECOPD patients (43.87±14.26) as compare to stable COPD patients (50.15±22.22). The difference in both groups was found statistically significant. Mean RDW was significantly higher in AECOPD (19.65±7.75%) as compare to stable patients (15.85±5.55%). The difference in both groups was found statistically significant. Conclusion: Prolonged hospital stay was closely associated with increased RDW on admission in AECOPD patients. Elevated RDW may be an independent predictor for prolonged hospital stay in AECOPD patients