A previously described balloon tipped dilatation catheter has been used during revascularization surgery to dilate lesions which potentially could limit the runoff of the saphenous bypass grafts. A total of 34 lesions were dilated in 25 patients. Restudy of 12 patients (15 lesions) demonstrated positive results and no clinically significant complications. These preliminary results suggest an important role for transluminal coronary dilatation in the operative treatment of coronary artery disease.