In February 1979 a 51 year old man fell will in Munich, displaying symptoms of an influenza-like illness which developed into pneumonia. The patient died eight days later of circulatory collapse which failed to respond to treatment, accompanied by high temperature, leucopenia and agranulocytosis. Typical rods detected in the lung tissue and histological sections by immunofluorescence indicated the possibility of a Legionella pneumophila infection. The pathogen isolated from the lung tissue on CYE agar was identified as L. pneumophila, serogroup I. The diagnosis was confirmed by the CDC, Atlanta. This is the first time this organism has been isolated in Central Europe from a case with a fatal outcome.