Different PCR-based DNA fingerprinting techniques were evaluated for typing 26 clinical isolates belonging to the Acinetobacter calcoaceticus-A. baumannii complex. Seven isolates belonged to a previously defined outbreak while 19 isolates were unrelated epidemiologically. The PCR-based DNA fingerprinting techniques used were: (i) repetitive extragenic palindromic (REP) PCR; (ii) enterobacterial repetitive intergenic consensus (ERIC) PCR; (iii) randomly amplified polymorphic DNA with M13 forward primer; (iv) restriction analysis of the amplified 16S rRNA gene (ARDRA-16S); and (v) restriction analysis of an amplified region containing the 16S-23S rRNA spacer region and part of the 23S rRNA gene (ARDRA 23S + spacer). The discrimination index for the PCR-based DNA fingerprinting techniques was: 0.99 for REP; 0.94 for ERIC; 0.87 for M13; 0.60 for ARDRA-16S digested with Hpa II and <0.50 for ARDRA 23S + spacer. It was concluded that REP-PCR possessed high discriminatory power and reproducibility in comparison with the other PCR-based DNA fingerprinting techniques, and is a simple and rapid typing method for use in epidemiological studies of isolates belonging to the A. calcoaceticus-A. baumannii complex.