IMPORTANCE: There is an increasing need to prolong trabeculectomy success rates with minimally invasive procedures. OBJECTIVE: To investigate the safety and efficacy of Nd:YAG laser goniopuncture (LGP) in lowering intraocular pressure (IOP) in eyes having late bleb failure following trabeculectomy with mitomycin C administration. DESIGN, SETTING, AND PARTICIPANTS: Prospective, noncomparative, interventional cohort at a referral glaucoma practice, including 19 eyes of 19 patients with uncontrolled glaucoma after failed trabeculectomy. INTERVENTIONS: All eyes had ischemic nonfunctioning blebs with patent internal ostia and underwent Nd:YAG LGP, followed by a 5-fluorouracil injection. MAIN OUTCOMES AND MEASURES: The IOP and the number of antiglaucoma medications before and after the procedure, as well as presurgical and postsurgical appearance of the blebs, using the Indiana Bleb Appearance Grading Scale classification. RESULTS: The mean (SD) time of LGP after trabeculectomy was 35.7 (32.3) months, and the mean (SD) follow-up period after LGP was 6.0 (1.1) months (range, 4.4-8.4 months). The mean (SD) IOP had decreased from 20.9 (4.5) mm Hg (range, 15.5-29.0 mm Hg) to 11.9 (4.1) mm Hg (range, 5.0-21.0 mm Hg) (P < .001). The only complications observed after LGP were 2 cases of hypotony, which resolved spontaneously. Compared with baseline Indiana Bleb Appearance Grading Scale classifications, 2 eyes showed an increase in bleb height and 10 eyes showed an increase in bleb extension. None of the eyes had a positive Seidel test result. The mean (SD) number of hypotensive agents per eye had decreased from 0.7 (1.1) to 0.3 (0.7) after the procedure. At the last follow-up visit, 15 eyes (79%) had achieved an IOP of 15 mm Hg or less, with a minimum IOP reduction of 20% from baseline without medication use. CONCLUSIONS AND RELEVANCE: The Nd:YAG LGP is a safe and effective procedure for lowering IOP in eyes with ischemic nonfunctioning blebs and patent trabeculectomy ostia. This is a promising solution to rescue failed trabeculectomies and can potentially prolong trabeculectomy success rates.