We report a case of severe pulmonary hypertension in a patient with human immunodeficiency virus(HIV) infection. A 29-year-old woman with asymptomatic HIV infection was diagnosed as atrial septal defect(ASD) and severe pulmonary hypertension. Chief complaint was dyspnea of NYHA functional class III and signs of right heart failure. The echocardiogram showed moderate tricuspid regurgitation with severe pulmonary hypertension and secundum type ASD as well. With the impression of ASD with pulmonary hypertension, surgical repair of ASD was done. Despite the surgical correction of ASD, the pulmonary hypertension and signs and symptoms of right heart failure did not improve. So under the impression of HIV-related pulmonary hypertension, we used a oral endothelin-1 receptor antagonist, bosentan. With the use of bosentan, the pulmonary artery pressure dropped gradually to near normal and signs and symptoms of right heart failure were improved. In conclusion, pulmonary hypertension is a rare but life-threatening complication of HIV infection and bosentan, a oral endothelin-1 receptor antagonist, can be a effective therapeutic option in such a case.