To compare the efficacy and safety of combined phacoemulsification-goniotomy to phacoemulsification alone on intraocular pressure (IOP) primary open-angle glaucoma (POAG) patients. Design: A comparative retrospective research. Patients and Methods: The study included 2 groups with POAG & cataracts. Group (Ph) included thirty patients who had phacoemulsification alone; while Group (PhG) included thirty patients who had combined phacoemulsification-goniotomy. They were further divided into severe (Phs and PhGs) and moderate (Phm and PhGm) glaucoma groups depending on the level of glaucoma. We recorded the medicated preoperative IOP, number of glaucoma drops, and postoperative IOP for all patients. We followed up patients for 24 months for IOP and the number of IOP lowering drops. All complications were recorded and managed.Results: On the first postoperative week, Group (Ph) recorded a reduction of IOP from 35±0.54 and 33±1.9 to 31±0.83 and 28±1.2 mmHg in groups Phs and Phm, respectively. Therefore, we needed to reintroduce the IOP lowering medications for all patients in group Ph with no significant drop in the number of IOP lowering medications by the 24-month follow-up. In group (PhG), we noted a significant fall in postoperative IOP in the first follow-up week from 34±0.29 and 31±0.9 to 26±1.2 and 14±0.9 mmHg in groups PhGs and PhGm, respectively (P-value <0.0001).Patients in Pm and PhGm groups stopped all IOP lowering medications, while those in Phs and PhGs groups needed less medications by the end of follow-up period. Conclusion: Combined Phaco-goniotomy shows higher efficacy with a good safety profile when compared to phacoemulsification in POAG patients regarding IOP control, particularly the moderate POAG.