The fat embolism syndrome is an uncommon clinical disorder that typically occurs as a complication of severe trauma. We report the case of a 60-year-old single-lung transplant recipient who died of massive fat emboli. Before lung transplantation, the patient had been treated with corticosteroids for at least 1 year because of chronic obstructive pulmonary disease caused by centrilobular emphysema and asthmatic bronchitis. After receiving his lung transplant, he was treated with triple-drug immunosuppression, which included 25 mg of prednisone per day. He was discharged from the hospital 2 months after transplantation only to be readmitted 2 weeks later with cytomegalovirus pneumonia, from which he recovered. Concomitantly, he had new lumbar compression fractures with severe back pain and lost approximately 3 cm in height during a 3-week period. On the eleventh day after hospital readmission, he suddenly had a "sepsis-like" illness without a known infectious cause, numerous petechiae and ecchymoses, marked pulmonary edema with worsening diffuse pulmonary infiltrates, profound hypoxemia, decreased mentation, and mild thrombocytopenia. He died 3 days later. With the exception of a positive sputum culture for cytomegalovirus, all cultures were negative. The postmortem examination showed severe osteoporosis, multiple vertebral compression fractures, and widespread massive fat emboli. This is the first reported case of fat emboli as the cause of death in a lung transplant recipient, and the case suggests that the fat embolism syndrome should be considered in the differential diagnosis of a sepsis-like illness in patients who have received steroids during a long period, particularly in the setting of vertebral compression fractures.