Purpose: To assess the effect of phacoemulsification and combined phacoemulsification-goniotomy on intraocular pressure (IOP) in patients with primary open-angle glaucoma (POAG). Setting: Benha University Hospital Design: A retrospective, observational, cohort study Patients and Methods: Sixty patients with cataract and POAG were allocated into two groups; group (P) had phacoemulsification, while group (PG) had combined phacoemulsification-goniotomy. Patients were subdivided into subgroups moderate (Pm and PGm) and severe (Ps and PGs) glaucoma based on the American Glaucoma Society classification of glaucoma severity. All patients had their presenting IOP, medicated IOP, number of IOP lowering medications, and postoperative IOP recorded. Postoperative IOP and IOP lowering drops number were followed up for 24 months after surgery. All intraoperative and postoperative complications were recorded and managed accordingly. Results: Group (P) showed an IOP reduction from 33±1.9 and 35±0.54 to 28±1.2 and 31±0.83 mmHg in subgroups Pm and Ps, respectively on the first postoperative week. All patients in group P needed to reinstate the IOP lowering drops with a non-significant change in the number of IOP reducing drops by the end of the study. In group (PG), a highly significant reduction in postoperative IOP was noted in the first postoperative week from 31±0.9 and 34±0.29 to 14±0.9 and 26±1.2 mmHg in subgroups PGm and PGs respectively P-value