Background: Ultrasound biomicroscopy (UBM), is a non-invasive technique used to visualize the anterior segment .The purpose of this study was to evaluate morphological changes in the anterior segment using UBM after phacoemulsification and IOL implantation. Methods: This was a prospective case series clinical study which was conducted on twenty eyes with senile or presenile visually significant cataract visiting the outpatient clinic of ophthalmology department, Benha university hospitals. Surgical technique consisted of phacoemulsification and foldable IOL implantation in the capsular bag . UBM was performed before and two months after surgery with (Sonomed Vumax II)device with a 35-MHz probe. the parameters measured were : Axial aqueous depth (AQD), Trabecular meshwork-iris angle (TIA) ,The angle opening distance at 500μm (AOD500),Iris thickness (IT),Trabecular meshwork-ciliary process distance (T-CPD) . Results: There was statistically significant difference between the mean of preoperative and postoperative IOP, also between the mean pre and postoperative BCVA. The current study showed that there was high statistically significant difference between pre and postoperative values of AQD ; with 1.0563mm mean difference (P