Nucleotide alterations in p53 intron 6 have been reported to be associated with the dysregulation of p53 function and tumor development. G13964C base change functioned as dominant mutation similar to the more common missense, nonsense and splice-site mutations. To detect the G13964C variant PCR-RFLP assay was used. In this study, DNA was isolated from colon cancer tissue samples of 35 cases (19 female and 16 male) diagnosed to be colon carcinoma. In this study, we found that mutations were present in 30 (85.7%) of 35 cases enrolled into study. In 7 (23.3%) cases G/G, 21 (70.0%) cases G/C and 2 (6.7%) C/C genotypes were found. In 5 (14.3%) cases DNA isolation could not be obtained. Our results indicate that heterozygotes for the GC allele have higher frequency than other alleles and one of the reasons of colon cancer may be related to GC allele frequency. [Turk J Cancer 2009;39(2):51-55]