Bronchiolitis obliterans organizing pneumonia (BOOP) has been described after bone marrow, lung, heart-lung, and renal transplantation, but rarely after orthotopic liver transplantation (OLT). We report a case of BOOP after OLT to emphasize BOOP as an under diagnosed and treatable cause of nonresolving pneumonia, which may not be preventable by maintenance low-dose prednisone. A 48-year-old man was hospitalized for dyspnea and cough one month after OLT. Among his medications were tacrolimus and prednisone. Physical examination was significant for lung crepitations and bilateral leg edema. Chest x-ray revealed bilateral infiltrates. Computed tomography (CT) of the chest demonstrated bilateral diffuse infiltrates with areas of sparing and nodularities. Bronchoscopy was normal and bronchoalveolar lavage was negative. Lung biopsy was performed and demonstrated serpiginous plugs of fibroblastic tissue filling the alveolar spaces, focal fibrosis of some alveolar septa, and reactive pneumocytic hyperplasia consistent with BOOP. Methylprednisolone was continued with clinical improvement and weaning from the ventilator, but subsequent sepsis and multisystem organ failure finally led to the patient's death.