Ralstonia paucula (formerly CDC group IV c-2) is an environmental organism that can cause serious human infections, occasionally clusters of nosocomial infections. In the present work, 26 strains of R. paucula (4 from the American Centers for Disease Control and Prevention collection, 10 from the Belgian Laboratorium voor Microbiologie [LMG] collection, and 12 French clinical isolates) were analyzed with infrequent-restriction-site PCR and randomly amplified polymorphic DNA analysis. Both techniques accurately distinguished between collection strains. Two close patterns obtained for all the French isolates suggested a clonal strain. Two LMG collection strains originating from human sources in the United States also showed patterns close to those of French isolates.