A case of capillary haemangiomatosis affecting both lungs. The angiomatous growth involved particularly the intralobular fibrous septa and appeared locally aggressive as it had destroyed and obstructed the pulmonary veins and venules. Some pulmonary arteries and bronchi were affected to a lesser extent. Pulmonary venous obstruction, sometimes simulating pulmonary veno-occlusive disease, caused severe haemosiderosis and interstitial fibrosis. The clinical features and the lung biopsy erroneously suggested a diagnosis of primary pulmonary haemosiderosis. No comparable case has been found in the literature.