In different types of cancer, SMAD7 rs12953717 polymorphism was significantly associated with an increased risk of colorectal cancer in all genetic models (homozygote comparison, OR = 1.34, 95%CI = 1.24–1.44, P<0.01; heterozygote comparison, R = 1.11, 95%CI = 1.02–1.22, P = 0.02; recessive model, OR = 1.25, 95%CI = 1.17–1.33, P<0.00001; dominant model, OR = 1.17, 95%CI = 1.07–1.28, P<0.01; allelic model, OR = 1.15, 95%CI = 1.11–1.20, P<0.01). Here, SMAD7 is linked to colorectal cancer.