Objectives: The objective is to describe a -year outcome of goniotomy using the Kahook Dual Blade (KDB, New World Medical Inc., Rancho Cucamonga, CA) in patients with primary open-angle glaucoma (POAG) either as a standalone or plus phacoemulsification (phaco). Material and Methods: We reviewed 12 eyes of 9 patients who had goniotomy with KDB either as a standalone or combined with cataract surgery by phaco from April 2017 to July 2018 at Eye Foundation Hospital, Ikeja, Lagos. The patients were followed for a minimum of 12 months. Results: The mean age of the patients was 66.4 ± 8.8 years. The mean pre-operative intraocular pressure (IOP) for all eyes was 18.58 ± 5.42 mmHg. After 12 months of follow-up, the mean IOP was 14.27 ± 5.22 mmHg, representing a drop of 4.31 mmHg (23.2%) from baseline. For the Phaco+KDB group, the mean IOP changed from 19.25 ± 4.56 mmHg to 15.0 ± 6.03 mmHg for the same period, representing a reduction of 4.25 mmHg (22.1%) from baseline, and for the KDB as a standalone, the mean IOP change was 4.25 mmHg (24.6%) from baseline (17.25 ± 7.45 to 13.0 ± 3.83 mmHg). For all eyes, the mean number of topical antiglaucoma medications dropped by 0.88 (36.4%) from 2.42 ± 0.90 to 1.54 ± 1.51, whereas for the Phaco+KDB group, the topical antiglaucoma medications were reduced by 1.17 (46.8%) from 2.50 ± 0.93 to 1.33 ± 1.50. However, there was no change in the number of topical antiglaucoma medications in the KDB group after 12 months of follow-up (2.25 ± 0.96 to 2.25 ± 1.50). Transient hyphema in one and posterior capsular opacity (PCO) were the only recorded post-operative complications. Conclusion: KDB, either as a standalone or with phaco, recorded at least a 20% reduction in IOP after one year of follow-up in these series.