Objective To explore the expression of RAD51 gene in colorectal cancer (CRC) and its relationship with clinicopathological features and prognosis.Methods The pathological specimens of 72 CRC patients were collected (CRC group, n=72), as well as the normal intestinal mucosa which was pathologically conformed with no tumor cells and was >3 cm away from the edge of the tumor (control group, n=72). The expression levels of RAD51 mRNA and protein in CRC and adjacent tissues were detected by qRT-PCR and Western blotting. The prognostic factors of CRC patients were analyzed by Cox proportional hazards model. The prognosis was analyzed by Kaplan-Meier and Log-rank methods.Results The relative expression levels of RAD51 mRNA and protein were higher in CRC group than in control group (P<0.05). The expression level of RAD51 in CRC was correlated with TNM stage (P<0.05). The high expression of RAD51 was an independent factor affecting 5-year overall survival rate and 5-year tumor-free survival rate of CRC patients (P<0.05). The 5-year overall survival rate and 5-year tumor-free survival rate of patients with low expression of RAD51 in CRC tissues were higher than those in patients with high expression of RAD51 (P<0.05).Conclusion RAD51 was highly expressed in CRC tissues, and it was related with TNM staging. CRC patients with high expression of RAD51 in tissues had poor prognosis. RAD51 may be a potential prognostic indicator for CRC patients.