Aim: To study the efficacy and safety of deep sclerectomy (DS) augmented with intraoperative low dose mitomycin C (MMC) in a west African population. Methods: Prospective,randomised,controlled trial. Trial participants were Nigerian patients with medically uncontrolled primary open angle glaucoma undergoing primary surgery at Maja Hospital,Lagos,Nigeria. 39 eyes of 39 patients undergoing DS were randomised into receiving intraoperative MMC 0.25 mg/ml for 2 minutes at the end of procedure (DS-MMC) and a control group (DSnoMMC). Results: There were 21 patients in the DS-noMMC and 18 in the DS-AAMC group with no difference in the preoperative characteristics of the groups. Mean follow up was 16.4 (SD 11.3) months. The probability of maintaining an intraocular pressure less than 18 mm Hg with or without additional medications (95% confidence intervals) at 1 year was 70% (47-92% ,95% ) and 79% (57-100% ),and at 18 months was 35% (8-62% ) and 38% (7-69% ) for the DS-noMMC and DS-MMC groups,respectively,with no difference in success rates (p = 0.6). An IOP of less than 18 mm Hg without additional medication was maintained in 65% (41-89% ) and 73% (49-96% ) at 1 year and 24% (8-48% ) and 13% (13-46% ) at 18 months for the DS-noMMC and DS-MMC groups,respectively (p = 0.5). There were no serious complications related to the procedure. Conclusions: The success rates of DS in black west African glaucoma patients,as performed in this study,were low. The study did not achieve sufficient power to detect whether low dose intraoperative MMCapplication can increase success rates of DS. Aim: To study the efficacy and safety of deep sclerectomy (DS) augmented with intraoperative low dose mitomycin C (MMC) in a west African population. Methods: Prospective, randomized, controlled trial. Trial participants were Nigerian patients with medically uncontrolled primary open angle glaucoma undergoing primary surgery at Maja Hospital, Lagos, Nigeria. 39 eyes of 39 patients undergoing DS were randomized into receiving intraoperative MMC 0.25 mg / ml for 2 minutes at the end of procedure (DS-MMC) and a control group (DSnoMMC). Results: There were 21 patients in the DS-noMMC and 18 in the DS-AAMC group with no difference in the preoperative characteristics of the groups. Mean follow up was 16.4 (SD 11.3) months. The probability of maintaining an intraocular pressure less than than 18 mm Hg with or without additional medications (95% confidence intervals) at 1 year was 70% (47-92%, 95%) and 79% (57-100%), and at 18 months was 35% (8-62 %) and 38% (7-69%) for the DS-noMMC and DS-MMC groups, r espectively, with no difference in success rates (p = 0.6). An IOP of less than 18 mm Hg without further education was 65% (41-89%) and 73% (49-96%) at 1 year and 24 (8-48%) and 13% (13-46%) at 18 months for the DS-noMMC and DS-MMC groups, respectively (p = 0.5). There were no serious complications related to the procedure. Conclusions: The success rates of DS in black west African glaucoma patients, as performed in this study, were low. The study did not achieve sufficient power to detect whether low dose intraoperative MMC application can increase success rates of DS.