The aim of this study was to examine the associations between the combined effects of urinary 8-Hydroxydeoxyguanine (8-OHdG) level and polymorphisms of XRCC1 Arg194Trp and XRCC1 Arg399Gln on the risk of urothelial carcinoma (UC). Here, XRCC1 is linked to urothelial carcinoma.