Purpose: To compare the effectiveness of limbus-and fornixbased conjunctival flaps in patients undergoing trabeculectomy with mitomycin-C augmentation. Meth ods: A retrospective review of the records of 71 consecutive eyes of 59 patients who underwent trabeculectomy with mitomycin C. All the patients had at least 6 months of follow-up. The first 35 eyes underwent surgery with a limbal-based f lap, whereas all subsequent surgeries were by fornix-based procedures. Results: No significant difference was detected between the groups with regard to patien t demographics, preoperative visual field and intraocular pressure parameters, p ostoperative intraocular pressures at day 1, months 1, 3, and 6 postoperatively, need for intervention, need for supplementary glaucoma medication, and final vi sual acuity. There were four cases of overdrainage and hypotony in the limbal-b ased group, whereas none occurred in the fornix-based group. In all 83%percent of eyes in the limbal-based group achieved intraocular pressures off medicatio n of less than 18 mmHg, whereas 94%of the fornix based group obtained such IOP control. One patient in the limbal-based group developed late postoperative end ophthalmitis. Conclusion: Trabeculectomy with MMC augmentation is a safe and eff ective procedure for reduction of IOP and visual rehabilitation whether a fornix -or a limbal-based conjunctival flap is utilised. In this series, there was a greater risk of excessive drainage with subsequent hypotonous complications when surgery was undertaken by a limbal-based procedure. Purpose: To compare the effectiveness of limbus-and fornixbased conjunctival flaps in patients undergoing trabeculectomy with mitomycin-C augmentation. Meth ods: A retrospective review of the records of 71 consecutive eyes of 59 patients who underwent trabeculectomy with mitomycin C. All the patients had at least 6 months of follow-up. The first 35 eyes underwent surgery with a limbal-based f lap, and all all subsequent surgeries were by forix-based procedures. Results: No significant difference was detected between the groups with regard to patien t demographics , preoperative visual field and intraocular pressure parameters, p ostoperative intraocular pressures at day 1, months 1, 3, and 6 postoperatively, need for intervention, need for supplementary glaucoma medication, and final vi sual acuity. There were four cases of overdrainage and hypotony in the limbal-b ased group, but none none in the fornix-based group. In all 83% percent of eyes in the limbal-based group achieved One patient in the limbal-based group developed late postoperative end ophthalmitis. Conclusion: Trabeculectomy with MMC augmentation is a safe and eff ective procedure for reduction of IOP and visual rehabilitation whether a fornix-a a limbal-based conjunctival flap is utilised. In this series, there was a greater risk of excessive drainage with subsequent hypotonous complications when surgery was undertaken by a limbal-based procedure.