SUMMARY Objective: To identify the mutation R579X in exon 18 located RB1 gene in patients with cervical lesions associated with human papilloma virus infection by PCR-SSCP, PCR-RFLP and sequencing. Method: Study of 72 samples of cervical brushing of the healthy women, infected with human papilloma virus and with cervical lesions that required DNA extraction, PCR amplification of exon 18 of the RB1 gene, PCR-SSCP, Sequencing and PCR-RFLP analysis. Results: PCR-SSCP analysis revealed two different band patterns. We indentified the R579X mutation in exon 18 of the RB1 tumor suppressor gene in 30.56 % of the experimental samples. Conclusions: The mutation found in the experimental samples leads to the formation of a non-functional truncated protein, in adition, human papilloma virus infection might contributed to the immortalization of cells with this mutation.