Objective: To investigate the effectiveness and reliability of posterior sub-Tenon triamcinolone acetonide (PSTA) application in branch retinal vein occlusion (BRVO)-related macular edema.Methods: Patients with confirmed BRVO-related macular edema were enrolled in the study. Patients were injected with a single, therapeutic dose of 40mg PSTA. Detailed ophthalmic examination was performed at baseline and at 1, 3 and 6 months after the treatment. Best corrected visual acuity (BCVA), intraocular pressure (IOP), cataractogenic change (CC) and macular optical coherence tomography (OCT) analysis results were evaluated. The results were compared statistically.Results: Forty-one eyes of 41 patients with a mean age of 63.4910.99 (55-86) years, 15 (36.6%) females, were included in the study. BCVA in LogMAR values at 1 and 3 months were significantly better than at baseline, while no significant difference from baseline was observed in sixth month values (p<0.001, p<0.001 and p=0.846, respectively). Central macular thickness values obtained using OCT were significantly lower at the first, third and sixth months compared to baseline (p<0.001 for all). IOP elevation was determined in only two eyes (4.8%) at the end of the study period, and no CC was detected in any case.Conclusion: PSTA application is an effective and safe option in BRVO-related macular edema.