A 60-year-old male with adult T-cell leukemia (ATL) complained of fever, cough and dyspnea, after anti-leukemic chemotherapy. Chest X-ray film showed a diffuse interstitial shadow, and cytomegalic inclusions and cytomegalovirus (CMV) antigen were detected in the bronchoalveolar lavage specimen and sputum. The diagnosis of CMV pneumonia was made, then ganciclovir and intravenous CMV-hyperimmune globin was administered. Although CMV pneumonia was improved with the treatment, the patient died of ATL. There was no cytomegalic inclusions in the lung but in the adrenal at autopsy. The combination therapy of ganciclovir and intravenous CMV-hyperimmune globulin is considered to be effective for CMV pneumonia.