From 1972 to 1979, 22 patients with end-stage renal disease underwent 23 cardiac operations involving the pump oxygenator. Fourteen patients had coronary artery bypass, 2 had aortic valve replacement, 2 had mitral valve replacement (MVR), 2 had MVR with coronary artery bypass, and 2 had ascending aortic root replacement with a composite graft. One patient underwent successful reoperation for a false aneurysm of the left ventricle after MVR. There were 2 postoperative deaths, for a mortality of 9.1%. The patients undergoing coronary artery bypass had an average of 2.7 grafts and an average Functional Class improvement from New York Heart Association Class III or IV to Class I or II. Eighteen patients required preoperative and postoperative dialysis to control blood volume, potassium, and uremia. Four patients had functioning renal transplants, and 4 patients underwent subsequent successful renal transplantation. We conclude that: (1) patients who have transplants and require dialysis can be successfully managed for cardiac operation in spite of their complex associated medical problems; (2) functional and symptomatic improvement simplifies continued management of the patient needing dialysis; and (3) improvement of a cardiac disability can allow favorable renal transplantation in selected patients.