Background: Microalbuminuria is a sign of glomerular dysfunction in general and sign of tubulointerstitial disease to a lesser extent. Hypoxia induces endothelial cell to release a number of different vasoactive agents including endotheline-1, platelet derived growth factor (PDGF), nitric oxide; that causes endothelial injury and lead to microalbuminuria. This study was aimed to assess the prevalence of microalbuminuria in COPD patients and assess the Relationship of microalbuminuria with the disease severity in the forms of FEV1, PaO2, PaCO2, and BODE INDEX in COPD patients.Methods: Total 130 COPD patients were included in our cross sectional study. Total patients were divided into two groups, 1st group was COPD with microalbuminuria while 2nd group was COPD without microalbuminuria. Lung function test, 6 min walk distance, arterial blood pressure (BP), BODE index, arterial blood gases, fasting and post prandial plasma glucose and kidney function tests were measured. Screening for microalbuminuria was done by measuring urinary microalbumin in a random spot urine collection.Results: The prevalence of microalbuminuria was 29.23% in patients of COPD. As compared with COPD without microalbuminuria group, COPD with microalbuminuria group were more hypoxic (12% vs 74%, P=0.0001 ), more hypercapnic (22% vs 84%, p=0.00001) and most of the patients with grade III (16% vs 34%, p=0.00001) or grade IV (19% vs 47%, p=0.00001) severity (according to GOLD criteria).Conclusions: Patients with severe COPD with hypoxemia or hypercapnia were significantly associated with microalbuminuria.