Background: Cytochrome P450 plays an important role in pharmaceutical metabolism, steroidal hormones and procarcinogens. CYP1A1 is an enzyme, which is very active in the formation of reactive mediators or injurious agents for DNA. The aim of this study is to evaluate the prevalence rate of genetic polymorphism RS 1048943 gene CYP1A1 in men diagnosed with prostate cancer compared to a control group of healthy men.Methods: This case-control study analysed blood samples from 79 patients with prostate cancer as well as 79 healthy men. Genomic DNA was extracted by the salting out method. After selecting the suitable primers from the papers, the samples were amplified for the considered segment and genotypes of the participants were determined by PCR-RFLP.Results: Individuals with prostate cancer had the following genotypes: AA (31.64%), GG (59.49%) and AG/GA (8.86%) compared to the control group that had genotypes AA (55.69%), GG (29.11%) and AG/GA (15.18%). According to the Hardy–Weinberg equilibrium, the frequency of allele A was 36.7% in the cancer group and 63.29% in the control group. The frequency of allele G was 63.92% in the cancer group and 36.70% in the control group. There were meaningful differences in the frequencies of homozygotes GG (P<0.001) and AA (P=0.002) between patients and controls.Conclusion: Polymorphism RS 1048943 in gene CYP1A1 is related to the risk of developing prostate cancer and it is likely one of the major factors in its occurrence.