Background To our knowledge, there is no useful and accurate prognostic biomarker or biomarkers for patients with oral squamous cell carcinoma (OSCC), a tumor with uncertain biological behavior, and unpredicTable clinical progress. The purposes of this study were: a) to determine the expresión profile of Connexin 43, Bcl-2, Bax, E-cadherin, and Ki67 in patients with OSCC; b) identify the GJCA1 rs12197797 genotypic composition. Material and Methods A cross-sectional study using genomic DNA and biopsy samples extracted from the oral mucosa with/without OSCC, older than 18 years, both genders, attended at Facultad de Odontología, Universidad Nacional Córdoba. Immunostaining for Cx43, Bcl-2, Bax, E-cadherin, and Ki67 and genotyping GJA1 rs12197797 by RFLP were performed. Odds Ratio (95% CI), Spearman Coefficient were estimated. Mann-Whitney test was applied to analyze immunostaining between controls/cases ( p <0.05 was set for statistical significance). Results GG (mutant) was the most frequent genotype in patients with OSCC diagnosis (53.2%) in relation to CC “healthy” genotype ( p =0.00487; OR=7.33; CI95% [1.1-54.7]). And, the allele G (mutant) had a presence in 75.5% of OSCC patients. However, no significant association was observed between alleles C/G and diagnosis ( p =0.0565). The heterozygous genotype was the most frequent in the patients of both groups Cx43 and E-cadherin markers were lower in OSCCs in relation to controls. Ki67 and Bcl-2 immunolabeling were high on OSCC, and Bax immunomarker was diminished in OSCC. Conclusions We hypothesized that the oral epithelium losses Connexin 43 and E-cadherin in the membrane, which modifies cell differentiation. The Ki67 and Bcl2 overexpression would increase the cell density in the tissue, by promoting proliferation and decreasing apoptosis. And, this study shows evidence that patients who carry on allele G of GJA1rs12197797 could be at risk of developing OSCC. Key words: Cx43, E-cadherin, Ki67, Bax, Bcl-2, immunostaining expression profile, GJA1 rs12197797 genotyping.