We describe a two-year-old boy suffering from pulmonary hypertension due to pulmonary venous stenosis. Previous reports suggest that it is not easy to diagnose this entity during life, and most cases are diagnosed at operation or autopsy. Our patient was diagnosed relatively early in life and treated successfully by pericardial patch venoplasty. Histologic examination of the lung biopsy performed at operation was considered to be useftil prognostically. The minimal pulmonary vascular changes noted were consistent with a good outcome after the surgical repair.