Background: trabeculectomy was considered gold standard procedure for glaucoma treatment. Mitomycin C (MMC) and bevacizumab (BVZ) has been used to increase trabeculectomy success rates. Objective: to compare the outcome of subscleral trabeculectomy with subconjunctival injection of BVZ with that of trabeculectomy with MMC. Patients and Methods: a prospective, non-randomized, comparative study design was used. Thirty eyes from thirty patients with uncontrolled glaucoma were enrolled. Fifteen eyes underwent subscleral trabeculectomy with intraoperative use of MMC (0.2mg/ml for 3 minutes) (group I) and 15 eyes underwent subscleral trabeculectomy with subconjunctival bevacizumab injection (1.25mg/0.1ml) (group II). The outcome measures were the best-corrected visual acuity, intraocular pressure (IOP), number of IOP-lowering medications, complications, and bleb morphologic features (based on the Indiana Bleb Appearance Grading Scale). Results: thirty eyes of thirty patients fulfilled inclusion criteria and assigned to one of two study groups. Each study group included fifteen eyes of fifteen patients. Participants were 14 males and 16 females. Mean ages of patients assigned to MMC and BVZ were 54.0±7.33 and5.7±6.9 years respectively. The difference in mean age was statistically insignificant among treatment groups (p=0.740). Mean number of pre-operative anti-glaucoma medications used by MMC and BVZ treatment groups were 2.47±0.52 and 2.47±0.52 with no significant difference among treatment groups (p=1.00). Conclusions: adjunctive subconjunctival bevacizumab with trabeculectomy is effective in controlling the IOP profile and the post-operative IOP reduction showed no statistically significant different in both group at all postoperative visits. Comparable success rates were achieved in the two groups.