In codon 72 of the p53 antioncogene there are two alleles, arginine and proline; the arg/arg genotype has recently been identified as a risk factor for developing of cervicouterine cancer (CuCa) associated to human papillomavirus (HVP) infection. The aim of this work was to determine in a sample of women the frequency of proline-arginine alleles and genotypes of p53 codon 72. The study was conducted in a sample of inpatient women at the hospital. p53 codon 72 alleles were determined in genomic ADN by amplification of specific sequences by chi 2 test. From 102 analyzed samples, p53-arginine allele corresponded to 67.64% and p53-proline allele corresponded to 32.36%; 47 women (46.10%) were arg/arg homocygotes, 11 women (10.77%) were pro/pro homocygotes, 44 women (43.13%) were arg/pro heterocigotes; the genotype distribution was within the Hardy-Weinberg equilibrium. The detection of a high percentage of arginine homocygotes suggests that this genotype, considered as a risk factor for cancer associated to oncogenic HPV, has a high prevalence in the north of Mexico. The determination of this kind of polymorphisms is important as preventive action with regard to identification of risk factors for CaCu associated to HPV infection.