PURPOSE: This study was performed to provide results 2 to 3 years after trabeculectomy with mitomycin C (MMC). METHODS: A consecutive series of all 68 patients who underwent trabeculectomy with MMC was analyzed using Kaplan-Meier life-table statistics and compared with other published retrospective analyses. RESULTS: At 2- and 3-year follow-up examinations, 59% (95% confidence interval [CI], 44-70%) and 47% (95% CI, 32-61%) of patients, respectively, avoided an intraocular pressure (IOP) of more than 21 mmHg or less than 20% below their preoperative level without glaucoma medication on two consecutive occasions more than 1 month apart after 3 months follow-up (75% [95% CI, 60-84%] and 70% [95% CI, 53-81%], respectively, with medication) and avoided additional glaucoma surgery. Loss of more than three lines of visual acuity on two occasions more than 1 month apart after 3 months follow-up occurred in 28% of patients (> 2 lines in 44%) at 3 years. Nonreversible causes of loss of three lines of acuity occurred in 13% of patients. Complications requiring reoperation occurred in 16% of patients and included hypotony maculopathy (4%) and late bleb leaks (4%). CONCLUSIONS: At the 3-year follow-up evaluation, trabeculectomy with MMC provided an approximately 50% chance of maintaining IOPs less than 21 mmHg and a more than 20% IOP reduction without concomitant use of glaucoma medication, which increased to 70% with the addition of medication. This procedure was associated with an approximately 30% risk of substantial visual loss (approximately 15% nonreversible) and a 15% chance of reoperation for complications.