Colorectal cancer (CRC) is the third most commonly occurring cancer worldwide. Intestinal cells are CYP27B1 gene expression sites and, as a consequence, they are capable of converting pro-vitamin D into the active paracrine and autocrine forms. It was demonstrated that rs10877012 polymorphism in the CYP27B1 gene influenced the circulating vitamin D level. This provided a rationale for determining the role that this polymorphism plays in the risk of developing colon cancer. In this study, we investigated the association of rs10877012 (T/G) polymorphism in the CYP27B1 gene with CRC susceptibility. The study population (n = 325) included CRC patients (n = 106) and healthy controls (n = 219). DNA was extracted from peripheral leukocytes and analyzed for the CYP27B1 polymorphism using the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method. We found an association between the presence of the T allele at the polymorphic site (odds ratio (OR) = 2.94; 95% CI 1.77–4.86; p < 0.0001) and a decreased CRC incidence.