Oral cancer is the sixth most common cancer in the world, and has the highest incidence in the South Asia. The TNM staging system cannot predict the biological behaviour and patient survival precisely. Therefore, histopathological grading system for oral squamous cell carcinoma (OSCC) in an attempt to provide additional information about biological behavior and prognosis of OSCC. The aim of this study is to assess the relationship between histologic risk assessment and clinical parameters of OSCC. This was a cross-sectional study. Histopathological examination of the surgical specimen was performed using the histological risk assessment grading system. The relationship between histologic risk assessment and clinical parameters were assessed by chi square test using SPSS v. 20.0. No significant association observed between the histologic risk assessment and tumor size, regional lymph node metastasis or clinical stage of the lesion. However, perineural invasion (PNI) was significantly associated with clinical stage of the lesion (P= 0.02), which indicates that PNI could be an important prognostic factor for understanding the biological behavior of OSCC patients. Therefore, we propose that every OSCC patient should be checked for perineural invasion.