A case of Corynebacterium equi infection in a renal transplant recipient is reported. This not uncommon pathogen of farm animals caused a lung abscess in a graft recipient who had received continuous immunosuppression with azathioprine and prednisone for seven years. Antibiotic therapy yielded radiological improvement, although the patient died from other causes. C. equi joins a growing list of rare opportunistic organisms which may cause disease in subjects who have received transplants.