Pulmonary haemosiderosis (PH) results from recurrent bleeding into alveolar spaces and interstitial lung tissue. If untreated, fibrosis and restrictive lung disease will develop and may lead to death. A distinction can be made between primary and secondary pulmonary haemosiderosis as a manifestation of auto-immune small vessel vasculitides, coagulation disorders or diseases with increased venous pressure. Interestingly, in some cases of 'idiopathic' PH, exposure to moulds and van Willebrand's disease may contribute to the pathogenesis. Haemosiderosis usually begins with haematemesis. Anaemia, alveolar infiltrates on chest x ray and siderophages in broncho-alveolar lavage fluid are diagnostic factors. Immunosuppressive treatment has improved the prognosis in recent years.