Carbapenem resistance in Enterobacteriaceae isolates has been reported from Turkey and is most often mediated by OXA-48 type carbapenemases. We report the identification and characterization of four carbapenem-resistant isolates (three Klebsiella pneumoniae and one Escherichia coli) among 515 clinical Enterobacteriaceae isolates collected during a 7-month study period in Ankara, Turkey. The four isolates were recovered from blood and urine specimens in patients with varied clinical manifestations. They had distinct pulsed-field gel electrophoresis patterns and harbored a variety of beta-lactamases including bla(TEM-1), bla(SHV-12) genes, bla(SHV-11), and/or bla(CTX-M-15). PCR and sequencing analysis revealed that the bla(OXA-48) gene was present in all four isolates. Our data indicated that the OXA-48-type carbapenemase was the only mechanism for carbapenem resistance in our hospital.