We found that the XRCC1 R399Q polymorphism was associated with a decreased bladder cancer risk among smokers (AA vs. GG: OR=0.693, 95%CI= 0.515-0.932, P=0.015 and recessive model AA vs. GA+GG: OR=0.680, 95%CI= 0.515-0.898, P=0.007, respectively). The gene discussed is XRCC1; the disease is urinary bladder cancer.