Background: Radiation-induced basal cell carcinoma (BCC) can be multiple, large, and recurring, which complicates its treatment in some cases. According to reports on the role of cyclooxygenase 2 (COX2) inhibitors in the treatment or prevention of non-melanoma skin cancers and considering the fact that COX2 expression has not been evaluated in radiation-induced basal cell carcinoma, weset out to assess the expression of COX2 in these lesions. Methods: In this study, COX2 expression was assessed by immunohistochemistry using anti-COX2 antibody on paraffinembedded blocks of 86 patients referred to Emam Reza Hospitalin Mashhad with BCC diagnosis by pathological examination (43 patients with and 43 without a history of radiotherapy) followed by semi-quantitative evaluation of COX2. Results: In our study, COX2 expression score was significantly higher in patients with a history of radiotherapy than those without radiotherapy (P<0.001). No correlation was found between theintensity and percentage of staining with sex, age, site of lesion, recurrence, and pathology of the tumor. Conclusion: Given the higher expression level of COX2 in the radiation-induced BCC patients, the use of COX2 inhibitors in these individuals may be effective in the incidence, recurrence, or treatment of BCC.