Background and aim: The incidences of both cataract and elevated intraocular pressure (IOP) increase with age. Elevated intraocular pressure is considered as important  risk factor for development and  progression of glaucoma. Determination of the type of glaucoma is  mandatory  to define the most appropriate therapeutic approach that used to decrease IOP. this study aimed to study the effect of phacoemulsification  surgery  on intraocular pressure (IOP) control in eyes with angle-closure glaucoma (ACG) and  eyes with open-angle glaucoma (OAG). Methods: Patients were divided into three group; Group I: 15 eyes (10 patients) with normal  physiological, range  IOP. Group II : 15 eyes (15 patients) with primary open angle glaucoma  (POAG). Group III: 15 eyes (15 patients) with primary angle closure glaucoma(PACG). Results and conclusion: Phacoemusification surgery had been shown to decrease IOP in eyes with or without glaucoma .Phacoemulsification had the potential to fulfill many features of an ideal approach to reduce intraocular pressure (IOP) compared with anti-glaucoma medications. As it lower the long term cost, and minimize systemic side effects also it result enhance visual acuity and contrast sensitivity after surgery and decrease time needed for post operative follow up . The magnitude of IOP reduction varies among patients. Postoperative IOPreduction was directly related with preoperative IOP values.so you might not expect IOP reduction postoperative when the preoperative IOP was not high.Patients with angle-closure glaucoma,  phacoemulsification is well established as an effective procedure result in IOP reduction.