Objective: To determine the efficacy and safety of ab interno trabeculectomy with Trabectome in juvenile open-angle glaucoma (JOAG) patients. Design: Prospective cohort study. Methods: Evaluation of the 12-month results of 2 patient groups receiving ab interno trabeculectomy: group 1, eyes with no prior incisional surgery; group 2, eyes that had prior incisional cataract or glaucoma surgery. Results: Group 1, 40 eyes (average age 31 ± 7 years), had a significant reduction in intraocular pressure (IOP) of 10.6 mm Hg at 12 months from a baseline of 27.4 mm Hg (p = 0.01), and the number of glaucoma medications reduced by 0.4 (p = 0.80). Four eyes (10%) within the study period required a secondary glaucoma surgery. Group 2, 20 eyes (average age 27 ± 8 years), had a significant reduction in IOP of 8.8 mm Hg from a baseline of 27.1 mm Hg (p = 0.06), and the number of glaucoma medications reduced by 1.4 (p = 0.36). Five eyes (25%) from this group underwent a secondary glaucoma surgery within 12 months. Conclusion: After 1 year of follow-up, ab interno trabeculectomy appears to be an effective and safe intervention for patients with JOAG; however, a reduction in use of topical medications may not be observed in those receiving ab interno trabeculectomy as a primary procedure.