Background: A pterygium is a fleshy, wing-shaped growth from the conjunctiva, crossing over the limbus onto the cornea. The tissue is fibrovascular and can occur over the nasal or temporal cornea. It can be a bilateral process and asymmetric with one eye affected by a larger pterygium than the other. Objective: To compare between the effects of intraoperative subconjunctival injection of Bevacizumab (Avastin) and intraoperative topical Mitomycin C on the outcome of primary pterygium surgery as regard efficacy and complications. Methods: Prospective, randomized, comparative clinical study was done on twenty eyes of twenty patients complaining of primary pterygium of variable duration that were surgically treated by simple excision. In addition to surgical excision, postoperative subconjunctival injection of bevacizumab was done for 10 eyes (group A), and postoperative application of mitomycin C (MMC) was done for 10 eyes (group B). The postoperative outcome was followed clinically for a minimum of 6 months and the main outcome criteria were recurrence rate and postoperative complications. Results: A significant high recurrence rate was found in bevacizumab group (60%) in comparison to MMC group (10%). In group A subconjunctival hemorrhage was detected in 2 cases while no complications were detected in group B. Conclusion: A single intraoperative subconjunctival injection of bevacizumab had decreased the recurrence rate after primary pterygium excision which seems to be marginally superior to bare sclera excision alone, but does not give a more desirable recurrence rate with insignificant complications as subconjunctival hemorrhage which resolved within 2 weeks.