The main aim of this study is to evaluate the interest of three-dimensional ultrasound perineal in the measurement of the levator hiatus area as an objective reflection of the surgical correction of pelvic organ prolapse (POP). Our hypothesis is that POP surgery decreases the size of the levator hiatus area.A longitudinal and prospective study was conducted between April and July 2017 in the Department of Gynaecology & Obstetrics at University Hospital of Angers. Surgery was performed either by laparoscopy (sacrocolpopexy) or vaginal surgery (with or without the use of mesh). All patients were handed an information letter and signed an informed consent before being included in the study. A questionnaire was fullfilled before and one month after surgery. A clinical evaluation using the simplified POP-Q classification and a perineal 3D ultrasound were carried out before and after surgery by the same professional. The levator hiatus area was assessed before and after surgery in order to evaluate the impact of surgery on the levator hiatus area. Simplified POP-Q measurements and responses to PFDI-20 and PFDI-7 questionnaires were also collected.A total of 18 patients were included in the study and four were excluded. Seven underwent laparoscopic surgery and seven underwent vaginal surgery. The levator hiatus area decreased substantially from 20.87 to 16.55 cm on mean (p = 0.0001) at rest. Regarding patient satisfaction, the PFDI-20 score improved after surgery from 89.36 to 37.87 on mean (p = 0.006), but the PFIQ-7 score did not reveal any significant changes (p = 0.096). For the clinical examination, we used the simplified POP-Q with Ba measurement from 2.3 to -1.92 cm (p = 0.005) or Bp from -1.5 to -2.46 cm, which is not a significant change (p = 0.14). Points C (or D in cases with a history of hysterectomy) changed from -3.1 to -6.15 cm (p = 0.03).The levator hiatus area seems to decrease after POP surgery. 3D ultrasound seems a new and complementary procedure that allowed to evaluate objectively the levator hiatus area and thus the clinical findings of the surgery.