This study aimed to assess the long-term course of pulmonary arterial hypertension related to infection with human immunodeficiency virus (PAHRH) and the influence of antiretroviral therapy (ART) on its characteristics. We retrospectively analyzed all 47 patients in the Swiss HIV Cohort Study in whom PAHRH was diagnosed. Among 35 patients who underwent follow-up Doppler echocardiography, the right ventricular systolic pressure over right atrial pressure gradient increased by a median of 25 mm Hg in 9 patients who had not received ART, decreased by a median of 3 mm Hg in 12 patients who had received nucleoside analogs, and decreased by a median of 21 mm Hg in 14 patients who had received highly active ART (HAART) (P<.005). Among all 47 patients, median duration of survival after PAHRH diagnosis was 2.7 years. HAART significantly decreased mortality due to PAHRH as well as other causes. This study suggests a beneficial effect of combination ART in patients with PAHRH.