Background: Oral lichen planus (OLP) is an autoimmune chronic muco-cutaneous disease that greatly affects the quality of life of LP patients with a progressive rate of malignant transformation. Diabetes Mellitus (DM) is assumed to be a globally affecting metabolic disorder that is exceedingly rising with a disturbing rate. Studies focusing on the association between LP and DM are still inconsistent. Objectives: This study aimed to analyze and compare the salivary levels of antioxidants GPx & SOD in the four groups of OLP, DM, OLP with DM and the healthy control, and to establish a correlation between the association of oral lichen planus with diabetes. Materials and method: 44 subjects were enrolled in this prospective cohort study. The patients were divided into four groups, 11 in each group: healthy control patients (group A), OLP (group B), DM (group C) and OLP with DM (group D). The salivary levels of antioxidants GPx &SOD were analyzed and compared to establish a correlation between the association of OLP with DM. Results: The mean GPx levels were highest in group A ,then, group C followed by group B, while group D had the lowest mean GPx level. The mean SOD levels were highest in group A followed by group C then group B while group D had the lowest mean SOD levels with insignificant difference between them. Conclusion:. Antioxidants play a vital role in human body, with a relationship existing between oxidative stress, hyperglycemia and cellular dysfunction.