Purpose: To evaluate the long-term visual and surgical outcomes, and associated risk factors for poor outcomes in patients with primary congenital glaucoma (PCG). Methods: Retrospective review of medical records of children who underwent combined trabeculotomyÀtrabeculectomy (CTT) without mitomycin-C as the first surgical procedure by a single surgeon between January 1990 and December 2010. Success was defined as intraocular pressure (IOP) <16 mmHg without (complete) or with (qualified) one glaucoma medication. We used the WHO criteria of vision loss to categorize the levels of vision impairment (VI). For purposes of statistical analysis, we randomly chose one eye of patients for bilateral PCG and affected eye in unilateral PCG. Results: The cohort included 653 consecutive PCG patients (1128 eyes; mean age, 26 months), of whom 475 (73%) underwent simultaneous bilateral CTT. Kaplan-Meier survival analysis revealed 1-, 5-, 10-, 15-, and 19-year complete success rates of 92.6% (n = 372), 75.5% (n = 173), 55.9% (n = 72), 44.7% (n = 19), and 21.6% (n = 3), respectively. Multivariate analysis revealed independent associations between failure, preoperative corneal clarity, and prior glaucoma surgery. Mean follow-up was 41 AE 51 months (range, 6 months to 19 years; median, 1 year). Of the visual acuity (VA) data in the affected eyes obtained at last follow-up (n = 333, 51%), seventy-four patients (22%) had VA of ≥6/12. Of the remaining 259 patients, 18 (7%) had mild VI, 87 (34%) had moderate VI, 58 (22%) had severe VI, and 96 (37%) were blind. No serious complications were noted. Conclusions: Primary CTT may be safely employed to control IOP and may provide long-term benefits in PCG patients.