We started to perform MIDCAB for the cases of markedly low cardiac function from June, 1996 and obtained satisfactory results. So we expanded the indications to include only left anterior descending artery (LAD) lesion from June, 1997 and have since performed this operation on 14 cases. The 14 cases of MIDCAB were divided into two groups, Group L consisting of 6 low risk cases: 1 lesion alone without any complications involving other organ before operation and Group H made up of 8 high risk cases: multi branch lesion but rated as high risk because of the extracorporeal circulation being used. Both Group L and Group H were free of operation death and hospital death. In Group L, all the cases underwent operation without blood transfusion, the period of postoperative stay in ICU was not longer than 1 day, on catecholamine was required after operation and complications were not found either. The patency of the graft was 100 percent. The patients were discharged 13.7 days after operation. In Group H, 2 cases required blood transfusion and 3 cases required catecholamine after operation. Complication arising from operative wound were noted in 3 cases. One GEA graft to the right coronary artery and one LITA to the LAD buried in the muscle were occluded. After operation, hospital stay for 23.9 days was required. In Group L, the postoperative course was excellent, so MIDCAB was considered indicated well for this group. In Group H too, the selection of MIDCAB was considered adequate that the risk of conventional CABG is considered much higher.