Severe oyknibart arterial hypertension is a life-threatening disease with a poor prognosis. Continuous intravenous infusion of prostacyclin has proved effective in this condition. However, it carries the risk of serious complications arising from the complex delivery system along with a high cost. Prostacyclin analogs, endothelin antagonists, and the phophodiesterase-5 inhibitor sildenafil are emerging and promisinge therapies. Tadalafil, like sildenafil, is a selective phosphodiesterase-5 inhibitor with a longer duration of action. We repport the use of tadalafil in two patients of severe pulmonary arterial hypertension who could not afford expensive treatment.