We report the use of pulsed-field gel electrophoresis (PFGE) and enterobacterial repetitive intergenic consensus (ERIC)-based polymerase chain reaction (PCR) to characterize clinical isolates of Pseudomonas aeruginosa serotype O11 collected from an incident of hospital-acquired infection. Both typing techniques differentiated 20 different strain types among seven epidemiologically related isolates and 22 epidemiologically unrelated isolates. There was complete concordance between these two techniques. Our results indicate that the ERIC-based PCR technique represents a rapid and simple means for typing P. aeruginosa serotype O11 with a level of discrimination equivalent to that of PFGE.