Objective: Minimally invasive direct coronary artery bypass (MIDCAB) surgery in the awake patient with epidural anesthesia had been previously reported. However, there is no prospective randomized study comparing MIDCAB surgery with epidural anesthesia versus general anesthesia. Methods: The study was conducted as a prospective and randomized study. Between January 2002 and May 2003, 76 patients were randomly assigned into either MIDCAB under general anesthesia (GA Group) or MIDCAB under epidural anesthesia (EA Group). The EA Group patients did not receive concomitant general anesthesia and they were conscious throughout the procedure. All patients had a left internal thoracic artery to left anterior descending coronary artery bypass using the same MIDCAB techniques. There were 42 patients in the GA Group and 34 patients in the EA Group. For statistical analysis, unpaired t-test for independent samples was used for comparison of continuous variables, and Pearson Chi-Square test was used for comparison of discrete variables. Results: The demographic characteristics of the groups were similar. There was no mortality or major morbidity in both groups. The EA Group patients had lower arterial oxygen saturations (93.3±3.2% versus 97.4±1.3%, p<0.001) and higher partial carbon dioxide pressures (45.8±3.6 mmHg versus 41.5±2.5 mmHg, p<0.001), but these were not clinically significant. The EA Group patients had significantly less intensive care unit (ICU) (5.5±6.5 hours versus 18.2±4.8 hours, p<0.001) and hospital stay periods (31.4±20.7 hours versus 58.6±17.9 hours, p<0.001), as well as significantly less postoperative pain (visual analog score 1.06±.6 versus 2.3±.6, p<0.001) and blood loss (184.2±169 ml versus 371.7±315.3 ml, p<0.001). There was no any difference in regard to patient satisfaction after the procedure between the two groups. Long -term results were equally satisfactory in both groups. Conclusions: It can be concluded that, similar surgical results can be achieved by MIDCAB surgery with general or epidural anesthesia. Although epidural anesthesia has no impact on the degree of patient satisfaction after the procedure, it yields significantly shorter ICU and hospital stay periods, which may result in more efficient use of hospital resources.