INTRODUCTION Oral Squamous Cell Carcinoma (OSCC) affects global health with increasing incidence and mortality rate. It may involve exposure to carcinogens from tobacco smoking or chewing. Alteration in expression of gene encoding the enzymes concerned with carcinogen biotransformation along with oxidative stress may increase or decrease the risk of cancer. AIM To evaluate the expression of CYP1B1 gene in OSCC patients along with its relation with oxidative stress and phase 2 detoxification enzyme status. MATERIALS AND METHODS In the present study, CYP1B1 genotypic analysis was carried out along with estimation of serum Total Antioxidant Activity (TAA), erythrocyte Malondialdehyde (MDA) levels and serum Glutathione-S-Transferase (GST) activity in 20 OSCC patients and statistically compared with that of age matched 20 healthy subjects, served as control by using student's t-test. RESULTS It was observed that 85% of histopathologically diagnosed OSCC patients had CYP1B1 expression with significantly elevated levels of MDA (p<0.001). In addition, plasma total antioxidant status and serum GST levels were decreased significantly (p<0.05) in OSCC patients as compared to the healthy controls to overcome the burden of oxidative stress. CONCLUSION On the basis of the present study, we conclude that the expression of CYP1B1 is an important determinant of carcinogenesis and significantly associated with oxidative stress characterized by decreased serum GST and total antioxidant levels in OSCC patients.