AIM: To compare the outcome of an Ex-Press implant and subscleral trabeculectomy (SST) in the management of glaucoma after previous trabeculectomy on a fibrotic bleb. METHODS: This randomized prospective study included 28 eyes from 28 patients (age range: 42-55y) with primary open angle glaucoma (POAG) presented with elevated intraocular pressure (IOP) with fibrotic bleb despite previous SST for more than 4mo. The eyes enrolled in the study were divided into two groups: group I (subjected to Ex-Press implant surgery) and group II [subjected to SST with mitomycin C (MMC)]. The follow-up continued one year after surgery to evaluate IOP, visual acuity (VA), visual field (VF), and postoperative complications. RESULTS: A significant decrease in IOP was found in both groups with a higher reduction in Ex-Press implant surgery with the mean IOP of 14.50 mm Hg (P=0.001), while the SST group recorded the mean IOP of 16.50 mm Hg (P=0.001) after one year. However, the difference between the two groups in terms of the decrease in IOP was insignificant. Fewer postoperative complications were recorded in the Ex-Press implant surgery and more cases requiring further anti-glaucomatous medications were seen in the SST group. Both groups showed stability in terms of VA and VF. CONCLUSION: Ex-Press implant surgery and SST with MMC are two surgical alternatives for controlling IOP in late failure that occurs more than 4mo after previous SST with a fibrotic bleb. However, Ex-Press shunt is a safer surgery with fewer complications.