Diabetics have a significantly higher incidence of major adverse cardiac events (MACEs) and in-stent restenosis (ISR) than nondiabetics after percutaneous coronary intervention (PCI). Predictors of MACEs and ISR are uncertain in diabetics. In recent studies, microalbuminuria and proliferative retinopathy have been believed to relate to progressive coronary atherosclerosis. We retrospectively studied 191 consecutive patients (mean age 65 +/- 9 years) with diabetes who underwent PCI to determine predictors of ISR and MACEs (defined as cumulative incidence of myocardial infarction, revascularization, or death from cardiovascular cause), with special reference to microalbuminuria and proliferative retinopathy. Of 191 patients, 106 (56%) had a follow-up coronary angiogram at 16 +/- 2 months. Of these 106 patients, 66 (62%) developed ISR. In the multivariate model, microalbuminuria or proliferative retinopathy did not achieve significant association with ISR. Serum high-density lipoprotein cholesterol levels were significantly associated with a lower incidence of ISR (odds ratio [OR] 0.928, 95% confidence interval [CI] 0.876 to 0.983, p = 0.011) and MACEs (OR 0.96, 95% CI 0.931 to 1.000, p = 0.048). Use of drug-eluting stents also had a negative association with ISR (OR 0.171, 95% CI 0.05 to 0.585, p = 0.004). Renal insufficiency was associated with higher MACEs (OR 3.19, 95% CI 1.45 to 7.031, p = 0.0039). In conclusion, serum high-density lipoprotein cholesterol levels were inversely associated with ISR or MACEs.