The effectiveness of initial trabeculectomy with adjunctive 5-fluorouracil (5-FU) for uncomplicated glaucoma in patients age 40 years or younger at the time of surgery was evaluated retrospectively in a consecutive series of 20 eyes of 20 patients. Fifteen patients had juvenile primary open-angle glaucoma, 4 had pigmentary glaucoma, and 1 had glaucoma associated with angle recession. Mean patient age was 26.8 +/- 9.7 years (range, 13 to 40 years) at the time of surgery. The mean total 5-FU dose administered was 27.8 +/- 8.8 mg (range, 15 to 45 mg). The intraocular pressure (IOP) decreased from 34.4 +/- 11.5 mmHg preoperatively to 10.5 +/- 4.0 mmHg postoperatively after a mean follow-up of 31.1 +/- 17.3 months (range, 11.5 to 70 months). Nineteen eyes (95%) had a postoperative IOP of 20 mmHg or less without pressure-lowering medications. One patient required additional medical therapy to control the IOP. Complications included bleb-related endophthalmitis (2 eyes) and hypotony maculopathy (1 eye).