The genetic similarity of carbapenem-resistant Pseudomonas aeruginosa strains isolated in the Hospital Universitário São Francisco, Bragança Paulista, São Paulo, Brasil, was evaluated by pulsed field gel electrophoresis (PFGE). A unique clone was detected among 5 of 7 isolates, suggesting that cross-contamination might have played a role in the spread of carbapenemresistant P. aeruginosa strains. Interestingly, a similar PFGE pattern was encountered in a P. aeruginosa strain isolated from Hospital São Paulo that was used as a PFGE control.