No association was found between pre‐diagnostic circulating IGF‐I concentration and overall bladder cancer risk (adjusted OR for highest versus lowest fourth: 0.91, 95% CI: 0.66–1.24, ptrend = 0.40) or UCC (n of cases = 776; 0.91, 0.65–1.26, ptrend = 0.40). This evidence concerns the gene IGF1 and urinary bladder carcinoma.