Recipients of organ transplants are at increased risk for infection both because of immunosuppression and because of the transfer of microbes through the donor organs. We report two cases of M. tuberculosis disease in recipients of single lung transplants who shared a common donor. Both recipients developed pulmonary tuberculosis, one having fever and pulmonary infiltrates and the other having subclinical disease with M. tuberculosis organisms being recovered from bronchoalveolar lavage. Restriction fragment length polymorphism analysis on both isolates of M. tuberculosis revealed a common source. The donor of both lungs had a normal chest radiograph and no known prior history of M. tuberculosis infection or disease. These cases are the first report of two single lung recipients developing pulmonary tuberculosis from a common donor.