Our objective was to investigate the relationship between IFNG (+874 T/A) polymorphism and cervical intraepithelial neoplasia (CIN) in a population of Brazilian women. Ninety-six women, CIN II (48) and CIN III (48) and 50 normal controls, were enrolled in this study. DNA was extracted from blood samples by the salting out method and polymerase chain reaction (PCR) amplified. IFNG genotyping was performed by the PCR-Sequence Specific Primer method, using the Cytokine Genotyping Tray. There were no differences in genotypic frequencies between CIN patients and controls. However, after sample stratification into CIN II and III, a higher frequency of the AA genotype in CIN II versus control group (P = 0.05) was observed. When the comparison was performed between CIN groups, a higher frequency of the AA genotype in CIN II versus CIN III (P = 0.05) was observed. This study suggests that IFNG +874 T/A polymorphism responsible for the genetic differences in interferon (IFN)-gamma production may influence the human papillomavirus (HPV) clearance and cervical malignant progression. Further understanding of the role of this cytokine may contribute to the development of a biomarker of HPV infection and resulting in the improvement of squamous intraepithelial lesions treatment.