In three greyhounds, free grafts of pronator teres muscle from the foreleg were applied to the left ventricular myocardium, and showed successful gross and microscopic survival of the graft six months later. The free grafts of skeletal muscle were transplanted as complete muscle bellies two weeks after preliminary denervation by median nerve neurectomy, and at the time of suture to the myocardium, the central end of the divided left phrenic nerve was implanted into the graft. The animals were normally active and preserved normal electrocardiograms after grafting. The use of such grafts in clinical cases of generalized myocardial degeneration or major infarct is considered.