Atherosclerosis frequently develops in SVGs during the first 10 years. This process appears related to coronary risk factors. Several studies have found an association between hyperlipidemia and atherosclerosis documented at pathology. Late changes attributed to atherosclerosis that were observed at angiography were also significantly related to elevated serum levels of total cholesterol and triglycerides. They also were found in association with diabetes, systemic hypertension, and smoking in some studies. Several clinical studies have documented an association of one or several coronary risk factors with postoperative clinical events, including recurrence of angina, myocardial infarction, heart failure, reoperation because of clinical deterioration, and survival. These factors have been shown to act alone or in combination. The most important is an abnormal lipid profile and diabetes. Smoking and hypertension were seldom found to be significant predictors when considered separately, but appear to play an important role in association with the others. Control of coronary risk factors, particularly hyperlipidemia and smoking, seems mandatory in order to prevent SVG atherosclerosis and progression of the disease in the native coronary arteries.