One of the major causes of carcinogenesis is loss of genome stability. RAD51 in process of homologous recombination (HR) played crucial role in maintenance integrity of genome through initiate of DNA double strand breaks repair. Presence of single nucleotide polymorphism (SNP) in RAD51 gene could change the capacity of DNA repair and altered the response to damaging agents. Research on potential impact of genetic variability on development and progression CRC may contribute to setting new genetic markers or/and determined individual susceptibility to CRC.The aim of the study. This study was designed to evaluate the effect of 135 G/C (rs1801320) RAD51 polymorphism located in the 5' untraslated region on the risk and progression of CRC.Material and methods. The subjects consisted of histologically confirmed colorectal cancer (n = 200) and controls (n = 200) with lack of previous history of cancer. The distribution of genotypes was determined by restriction fragment length polymorphism PCR (RFLP - PCR). Statistical analysis was based on multivariate regression model.Results and conclusion. Our study reveal no significance association of 135 G/C RAD51 polymorphism with occurrence and progression of colorectal cancer.