Purpose: Carbapenem-resistant Klebsiella pneumoniae (CRKP) is an important nosocomial pathogen. The most common mechanism that causes carbapenem resistance in these bacteria is carbapenemase production. We aimed to study the molecular epidemiology of these K. pneumoniae isolates and the characteristics of carbapenem resistance. Materials and Methods: The diagnosis and antibiotic susceptibility tests of 62 CRKP isolates were performed with Vitek-2 automated system and E test. Carbapenemase genes were determined by multiplex PCR. The genetic relationships were detected by rep-PCR. Results: Eight clusters containing 25 strains with 95% or more similarity were identified by Rep-PCR method. On the other hand, 59.7% (37/62) of these strains were identified as "different" with similarities of less than 95% and more than two different bands. The blaOXA-48 gene was detected in 57 of the 62 isolates (91.9%) and the modified Hodge test was positive in all of the blaOXA-48 gene positive isolates. The resistance rates of carbapenems (imipenem, meropenem and ertapenem) were examined by Vitek-2 system and E-test. The lowest resistance rates were observed for meropenem (Vitek-2 35%, E-test 16%). Resistance rates in these isolates were 100% for ampicillin and amoxicillin-clavulanic acid, 90% for ceftriaxone. Conclusion: We found that OXA-48 oxacillinase production was responsible for carbapenemase resistance in CRKP. The rep-PCR results suggested that the genetic similarities between CRKP isolates were not high. We suggest that this was due to the characteristic of blaOXA-48 gene which is horizontal trasnferred rather. than clonal spread among bacteria.