After revascularization of the stored orthotopically transplanted liver both calcium and potassium are liable to fall to low levels when arrhythmias are common and ventricular fibrillation possible. These cardiac abnormalities are worsened by citrated blood transfusion and by the alkalosis which is artificially induced at this stage. It has been found safe to raise both potassium and calcium by a steady infusion over 2 h of 0.6 mEq/kg of calcium and 0.85 mEq/kg of potassium in a 10-percent glucose solution. This infusion has been started 5 min before circulation was restored through the donor liver in the recipient animal. Since the regimen was instituted cardiac arrhythmias have been less in evidence and ventricular fibrillation has not occurred.