Diffuse alveolar hemorrhage (DAH) is a life-threatening acute manifestation of systemic diseases, the most commonly of systemic vasculitis. Clinically DAH manifests by a rapidly progressive respiratory and renal failure. The decisive for diagnose is immediate bronchoscopic examination with the bronchoalveolar lavage examination. CT mostly show bilateral pulmonary infiltrates, in blood picture rapidly come to anemia. In the majority of patients it can be found positive ANCA antibodies. DAH should be suspected in the case of acute respiratory failure also in patients without history of systemic disease. On the set of 33 patients with acute DAH episode, we demonstrate the importance of rapid diagnosis and aggressive therapy. In a third of our patients was DAH the first manifestation of systemic disease. Immunomodulatory treatment must be initiated immediately after diagnose. Hospital mortality in our group was 27 %, although 42 % of the patients were required ventilation support and one-third of patients had acute renal failure. After handling of acute episode of DAH is the prognosis quoad vitam promising.Key words: bronchoalveolar fluid - diffuse alveolar haemorrhage - granulomatosis with polyangiitis - intensive care in rheumatology - vasculitis.