Legislation for brain death and organ transplantation was passed in Japan in 1997, but there is still a great shortage of brain-death donors. Primary pulmonary hypertension (PPH) is a progressive disease that is usually followed by death within 5 years of diagnosis. Continuous infusion of prostacyclin is effective, but some patients will ultimately require heart-lung or lung transplantation. The first case of bilateral living-donor lobar lung transplantation (LDLLT) for PPH in Japan is reported. The recipient was a 19-year-old woman who was diagnosed as PPH at the age of 14 years and began intravenous prostacyclin therapy. Initially her symptoms improved, but she returned to New York Heart Association class IV in 2000. In January 2001, she underwent bilateral LDLLT. Postoperative echocardiography showed that the right ventricular diameter had decreased and septal wall motion had normalized, resulting in a round-shaped left ventricle. Right heart catheterization demonstrated that cardiac output and pulmonary arterial pressure had normalized. The right ventricular ejection fraction improved from 15% to 77%. The patient was discharged from hospital after 60 days postoperatively. LDLLT will become one of the options in Japan for end-stage PPH.