Atherosclerosis is called as a systemic disease of the vessel wall that occurs in coronary arteries. The atherosclerotic plaques may cause the narrowing (stenosis) of coronary arteries or complete occlusion of the arteries that leads to heart attack and strokes. X-ray angiography has extremely assisted in the diagnosis of atherosclerosis in patients. During image acquisition the images acquired are degraded due to the presence of noises and artefacts and the clinician find very difficult to diagnosis the stenosis. Therefore there is a need to improve the quality of the image for the easy diagnosis of stenosis. This paper focuses on enhancement of coronary artery blood vessels by mono modal image fusion techniques based on discrete wavelet transform for the easy diagnosis of stenosis. Peak signal to noise ratio (PSNR) computed for a different wavelet filter was used to evaluate the performance of the proposed method. The features are effectively preserved and the simulated result shows that this method enhances the quality of the image in a better way.