Purpose: This study was aimed to evaluate the stress oxidative status with the nitric oxide (NO) index in a sample of Iranian population.

  Materials and Method: In this descriptive-comparative study, serum NO level was assessed in 20 OLP patients as the case group and 20 healthy individuals as the control group. Collected data were analyzed by adopting two Sample t-test, using SPSS 16 software. The statistical significance level was set at p< 0.05. 

  Results: The mean serum NO levels in OLP patients and healthy controls were 17.1±3.4 ng/ml and 14.5±2.7 ng/ml respectively which revealed a significant statistical difference (p= 0.009). 

  Conclusion: The results of the current study with its limitation may support the premise that higher serum levels of NO in patients with OLP might activate the process of lymphocytes and cellular immunity system hence, possibly endorsing the effect of serum NO in pathogenesis of lichen planus.