Infection is a well-recognized complication of immunosuppressive therapy. We describe a case of leishmaniasis in a 62-year-old man who was undergoing immunosuppressive therapy because of heart transplantation. A geologist and native Texan, the patient had traveled extensively in south-central Texas, but not outside of the continental United States. Cutaneous lesions of the extremities developed, which were diagnosed histologically as leishmaniasis and confirmed by means of transmission electron microscopy. Cultures grew Leishmania mexicana. Treatment with sodium antimony gluconate was successful in healing the infective lesions.