A Legionella-like organism (strain 72-OH-H [= ATCC 43753]) was isolated from an open-lung biopsy specimen from a hemodialysis patient with end-stage renal disease and bronchopneumonia. Growth characteristics and gas-liquid chromatographic profiles of the isolate were consistent with those for Legionella spp. The isolate was presumptively identified as a Legionella longbeachae serogroup 1 strain by direct immunofluorescence staining. However, the organism was serologically distinct in the slide agglutination test with absorbed antisera. DNA hybridization studies showed that strain 72-OH-H constitutes a new Legionella species, which is named Legionella cincinnatiensis (ATCC 43753).