The present study was designed to assess the therapeutic effect of sildenafil in children with pulmonary hypertension. The study population included 15 patients with pulmonary hypertension of varied etiology. Sildenafil improves overall clinical status in all parameters and provides statistical improvement in ESPAP with few adverse events which were not recurrent. Sildenafil is expensive. However, this compares favorably with the estimated costs of one year's treatment with intravenous epoprostenol or inhaled prostacyclin, which till date are unavailable in our country.