Using a 5 X 5-mm ultrasonographic Doppler miniprobe, the flow volume of arterial grafts (internal thoracic artery and gastroepiploic artery) was measured four times during the course of coronary artery bypass grafting. Graft flow just before sternal closure was almost equivalent to that in the preoperative phase when the anastomosis was optimal. Use of the Doppler miniprobe facilitated evaluation of the arterial graft flow pattern easily and quickly. We conclude that the Doppler miniprobe can provide helpful information for the evaluation of results of coronary artery bypass grafting in real time without necessitating any additional procedures.