Oral carcinogenesis is a multi-step process, affecting predominantly elderly males with a long history of smoking and alcohol drinking while the role of infectious agents in its progression has not been fully identified. Human cytomegalovirus (HCMV) has been hypothesized in the oral pathogenesis and carcinogenesis. Usually, p16 protein is absent in oral squamous cell carcinoma (OSCC), either for p16 gene being mutated or deleted or its expression being abrogated while p16 expression is associated with favorable prognosis. Is to analyze the concordant impact of p16 expression and HCMV infection on tissues from a group of patients with Oral squamous cell carcinoma (OSCC) in mid-Euphrates-Iraq. One-hundred formalin-fixed, paraffin- embedded Oral tissues enrolled in this study; 40 oral tissue-biopsies from Oral squamous cell carcinoma (OSCC); 40 tissues obtained from patients with benign oral tumors and 20 apparently healthy oral tissues were used as control group. Detection of HCMV was done by chromogenic in situ hybridization (CISH) technique while the protein expression of p16 gene by using immunohistochemistry (IHC) detection system. In OSCC group, the hCMV-positive CISH and the p16-positive IHC reactions were detected in 42.5% and.52.5% of tissues, respectively. The correlation between HCMV and P16 was highly significant (P= 0.003). The significant co-expression of P16 and HCMV genes in OSCC tissues could point for their possible role in either oral pathogenesis or carcinogenesis.