Organizing pneumonia (OP) is a well histopathologically defined disease, which can be induced by many factors--infections, drugs, connective tissue diseases etc. In many cases a rapidly progressive course is observed with clinical picture of pneumonia. We report a case of organizing pneumonia with an acute onset and rapid deterioration in 58-year-old women. After unsuccessful treatment with antibiotics, prompt biopsy of the lung (videothoracoscopy) helped to establish the diagnosis. A rapid improvement after corticoid therapy was observed. Low dose corticoid treatment is continued. Patients remains well 20 months after onset of symptoms.