Background: Coronary artery disease (CAD) is a major cause of mortality and morbidity in many countries. Atherosclerosis of coronary arteries is responsible for almost all cases of CAD. Pathology of endothelium is the main cause of atherosclerosis of coronary arteries. Coronary artery disease is affected by many factors and several different risk factors. Objective: To investigate the association between the level of microalbuminuria and the severity of coronary artery disease angiographically. Patients and Methods: The study was conducted on 100 patients who underwent coronary angiography in Cardiology department of Al-Azhar faculty and 6 October Cardiology Hospital on selective basis. The population study was divided into 2 groups according to microalbuminuria. Group (I): included 66 patients with angiographic evidence of coronary heart disease and without microalbuminuria. Group (II): included 34 patients with angiographic evidence of coronary heart disease and having microalbuminuria. Results: In the present study it was found that increased severity of coronary artery disease was more prevalent among patients with microalbuminuria compared to those with normoalbuminuria and the difference was statistically significant. Conclusion: Microalbuminuria is predictive for CAD independently with other risk factors. Microalbuminuria increase severity and number of CAD lesions and aggressive treatment of microalbuminuria may be beneficial in CAD patients.