---

Background and Objective: Pterygium is a fibrovascular lesion of the ocular surface with unknown origin, decrease in the vision. This study was done to evaluate the possible role of Epstein-Barr virus (EBV) in the formation of pterygia. Methods: This case-control study was done on 50 tissue specimens of pterygium from the patients who underwent pterygium surgery as the case group and 10 conjunctival biopsy specimens of individuals without pterygium including the patients whom underwent cataract surgery, as controls. The evidence of EBV infection was tested by polymerase chain reaction (PCR). Results: EBV was detected in three (6%) patients with pterygia. EBV was not detected in controls. There was not any significant correlation between pterygium and the presence of EBV. Conclusion: According to this study, EBV virus is not associated with pterygium formation.