We studied coronary artery bypass grafting (CABG) in patients with renal dysfunction. From April 1994 to October 1999, 59 patients with renal dysfunction underwent CABG. The patients were divided into 2 groups: group A: 18 patients with end stage renal disease who were receiving hemodialysis, group B; 41 patients with creatinine levels higher than 1.5 mg/dl who were not supported by dialysis. We compared and analyzed the findings of there 2 groups. Regarding preoperative factors, the incidence of old myocardial infarctions, diabetes mellitus and old cerebral infarctions did not differ significantly between the 2 groups. Regarding perioperative factors, the incidence of the number of vessel diseases, emergency operations, operation times and blood transfusions did not differ significantly between the 2 groups. Regarding the post-operative course, the hospital mortality rates demonstrated low levels in 2 groups. The graft patency of group A was 95%, while it was 99% in group B. The post-operative in-hospital days was 24.8 days in the group A, while it was 30.1 days in the group B. No significant difference was observed between the 2 groups. As a results, post-operative hemodialysis was needed in 8 of the patients who underwent on-pump CABG from group A. The actual survival rates were 75.3% in group A and 84.3% in group B at 4 years. The cardiac event free rate for group A was 93.3%, while it was 97.5% in group B at 4 years. In conclusion, CABG may improve the post-operative outcome in renal dysfunction patients. In addition, the use of off-pump CABG is also considered to achieve a better renal function than on-pump CABG.