We aimed to investigate a potential effect of genetic polymorphisms in genes XRCC1 (Arg399Gln), OGG1 (Ser326Cys), XRCC3 (Thr241Met), and XRCC4 (Ile401Thr) on the level of DNA damage and repair in COPD patients and controls. Here, XRCC3 is linked to chronic obstructive pulmonary disease.