Reported here is a rare case of atypical pneumonia due to a non- pneumophila Legionella sp. that occurred in a young patient with systemic lupus erythematosus. In spite of aggressive treatment, the patient died 24 h following admission to the intensive care unit. Legionella longbeachae was cultured from respiratory tract specimens and identified to the genus level by PCR and to the species level by an immunofluorescence test. Since most current laboratory tests for Legionella spp., including urinary antigen and serology, cannot detect infections caused by non- pneumophila Legionella spp., culture on legionella-selective media should be strongly considered when diagnosing immunosuppressed patients with pneumonia.