We present a 30-year-old man with pulmonary hypertension after pulmonary embolism. Pulmonary angiography showed multiple stenoses in the pulmonary vascular tree. We treated four of these stenoses by balloon angioplasty in three sessions. Pulmonary artery pressure was reduced from 90/25 mm Hg (mean 46) to 78/13 mm Hg (mean 35) with concomitant increase of aortic pressure from 105/60 mm Hg (mean 75) to 134/68 mm Hg (mean 90). Pulmonary perfusion scintigraphy showed increase of perfusion in the treated segments. Two procedures were followed by transient segmental pulmonary edema, but no other complications were noted. We conclude that balloon angioplasty is a promising method of lowering pulmonary artery pressure and improving pulmonary perfusion in suitable cases of pulmonary hypertension secondary to pulmonary embolism.