A 55-year-old female recipient of an orthotopic liver transplant, who was receiving azathioprine, prednisone and cyclosporin, developed bacteremia due to Listeria monocytogenes. Because of a penicillin allergy, the patient was treated primarIly with trimethoprim-sulfamethoxazole, to which she responded well. The prior literature on use of trimethoprim-sulfamethoxazole in listeria infections is reviewed, and future recommendations are considered. On the basis of the experience described in this case report as well as a review of the literature, trimethoprim-sulfamethoxazole appears to be an effective treatment of listeria infections.