PURPOSE To examine the relationship between the incidence of later cardiovascular events after abdominal aortic aneurysm (AAA) surgery and postoperative lipid levels. METHODS Atherosclerotic risk factors including postoperative serum lipid levels were examined in 116 patients aged 70 or less undergoing an elective AAA surgery. Later cardiovascular events after AAA surgery occurred in 21 patients, including cerebral infarction (n = 4), catheter intervention or surgery for coronary artery disease (CAD) (n = 10) and other vascular disease. RESULTS Postoperative cholesterol levels during the average follow-up period of 55.6 ± 44.3 (months) were 49.0 ± 15.7 (mg/dL) for high-density lipoprotein cholesterol (HDL-C), 97.9 ± 31.2 (mg/dL) for low-density lipoprotein cholesterol (LDL-C), which were both significantly improved compared to preoperative values (p <0.001). Cox hazard analysis indicated that preexistent CAD significantly increased in the risk for later cardiovascular events (hazard ratio 5.67; 95%CI 1.92-16.8; p = 0.002) and lowered postoperative LDL-C/HDL-C ratio <1.5 decreased in the risk after AAA surgery (hazard ratio 0.10; 95%CI 0.01-0.83; p = 0.033). Patients with postoperative LDL-C/HDL-C ratio <1.5 (n = 22) had a significantly better cardiovascular event-free rate than those with that ratio ≥1.5 (n = 94) (p = 0.014). CONCLUSION Lowered postoperative LDL-C/HDL-C ratio <1.5 can decrease in the risk for later cardiovascular events after AAA surgery. These results may support the rationale for postoperative aggressive lipid-modifying therapy.