Purpose To determine the role of the intraoperative triamcinolone acetonide application after pterygium excision using bare-sclera technique and mitomycin C (MMC). Patients and methods This prospective randomized clinical study included 80 patients (80 eyes) who had primary pterygium and was done at the Alpha Center of Ophthalmology. In total, 40 eyes were treated by excision with bare-sclera technique with MMC combined with intraoperative subconjunctival triamcinolone-acetonide injection (group I) (steroid group), and the other 40 eyes were treated by excision with bare-sclera technique with MMC alone (group II) (control group). All patients were subjected to complete ophthalmic evaluation preoperatively and were followed up for 6 months postoperatively. The postoperative conjunctival inflammation rate at 1 week was the primary outcome measure, while the rate of pterygium recurrence 6 months postoperatively and intraocular pressure (IOP) was the secondary outcome measure. No complications developed intraoperatively or postoperatively. Results The postoperative conjunctival inflammation was significantly higher in group II (45%) than group I (12.5%) (P=0.001). The recurrence rate of pterygium 6 months postoperative in group I was 7.5%, while in group II was 17.5%, which was statistically insignificant (P=0.176). The mean IOP 6 months postoperative in group I was 14.2±1.9, and in group II was 13.6±1.7, which was statistically insignificant (P=0.172). Pyogenic granuloma developed in one (2.5%) eye in group I and two (5%) eyes in group II. Conclusion After pterygium excision using the technique of bare sclera and MMC, the intraoperative subconjunctival injection of triamcinolone acetonide at the surgical site was found to be beneficial in reducing the incidence of postoperative conjunctival inflammation without elevation of the IOP and decreasing the recurrence rate of the pterygium.