Rhinovirus infections, although usually limited to the upper respiratory tract, can extend beyond the oropharynx and may cause complications in the lower respiratory tract, including pneumonia [1‐3]. We describe a case of rhinovirus pneumonia in an infant boy in which rhinovirus was recovered from the lung and analysis of hyperimmune serum to the causal rhinovirus revealed localization of rhinovirus antigen in the lung. At 16 and 22 days of age, an infant boy underwent operations for cardiovascular anomalies, including an interrupted aortic arch and a ventricular septal defect. After the operations, he developed transfusion-associated graft-versus-host disease and died of multiple organ failure at the age of 59 days. At autopsy, the histopathologic findings for the hematopoietic system and the skin were consistent with transfusionassociated graft-versus-host disease. Examination of the lungs showed mild hyperplasia of the bronchial epithelium with cytological alterations, thickening of the alveolar septum, marked hyperplasia of the alveolar lining cells, and desquamating swollen alveolar epithelial cells and macrophages in the alveoli; how