Pulmonary syndrome is defined by occurrence of lung involvement (alveolar haemorrhage) in association with renal failure (with a typical crescentic necrotizing rapidly progressive glomerulonephritis). It is caused by an autoimmune disease, most frequently ANCA-associated vasculitides and anti-GBM (glomerular basement membrane) disease. Early establishment of the right diagnosis and immediate treatment are crucial for favourable prognosis of the patients. First choice therapy includes high-dose corticosteroids and cyclophosphamide, usually with plasma exchange added. Newer therapeutic possibilities include especially rituximab even though there is limited experience with its use in the settings of the most severe cases of pulmonary syndrome.