We report three patients with pulmonary hypertension in Takayasu's arteritis, who showed long-term favorable response, clinically and hemodynamically, to the nitric oxide donor, molsidomine. In these patients, the inhaled nitric oxide was effective in reducing pulmonary artery pressure (PAP) and pulmonary vascular resistance (PVR) as was shown in the acute vasodilator response test using the invasive hemodynamic monitoring. Molsidomine (single oral dose of 4 mg) was also effective in reducing PAP and PVR in the acute test, but nifedipine was not. With 4 mg of molsidomine three times daily, their dyspnea, exercise capacity and hemodynamic parameters were improved. These favorable responses have lasted during the 1st and 3rd month follow-up in all patients.