Background: Recent studies suggest that single nucleotide polymorphisms in different genes may modulate the susceptibility to chronic inyelogenous leukaemia (CML). Here, the association of the common XRCC1 gene polymorphism Arg399Gln at codon 399 in CML was investigated. Patients and Methods: Genotyping was performed by melting curve analysis in samples from peripheral blood or bone marrow. Results: The frequency of the variant allele 399Gln was similar between the control group and the patients (35.2% and 34.9%, respectively; p=0.21). Similarly, the heterozygote and homozygote variant genotypes displayed a homogenous distribution in both groups (p>0.05 for all comparisons). Moreover, distribution of the variant allele and subgenotypes did not significantly differ between the patient subgroups with a diagnosis age below or above 50 years. Conclusion: To our knowledge, this is the first study to investigate the role of any XRCC1 polymorphism in CML and our findings do not support a role of codon 399Gln polymorphism in CML.