Twenty-three strains of Ornithobacterium rhinotracheale from various origins, associated with respiratory pathology of birds, were compared using plasmid profiles, ribotyping and Random Amplified Polymorphic DNA (RAPD) in order to achieve a precise strain characterization as well as to highlight the relationships between these strains. No plasmid could be detected. These strains were poorly discriminated by ribotyping although different enzymes were used. The RAPD analysis has given reproducible DNA fingerprints and a good level of discrimination. This method can be used with only one or two primers to differentiate the O. rhinotracheale strains and could be used in epidemiological studies.