PROSTHESIS FOR INGUINAL HERNIA REPAIR An implantable prosthesis (1) for repairing a hernia defect in an inguinal region of a human body delimited by the anterior abdominal wall, the psoas muscle and a medial inferior area of the inguinal anatomy, the prosthesis comprising: a piece (2) of biocompatible material having a preformed three-dimensional shape, the piece including: a first portion (3), intended to face the anterior abdominal wall, said first portion forming a partial spherical cap surface (8) shaped and dimensioned so as to substantially conform to the shape of the anterior abdominal wall, a second portion (4), intended to face the psoas muscle, said second portion extending from an inferior edge of said first portion and forming a wavy-shaped wall (9), shaped and dimensioned so as to substantially conform to the shape of the psoas muscle, wherein said piece (2) further comprises: a third portion (5) forming an arched part, said arched part extending longitudinally substantially in the inferior direction from a medial inferior comer (3a) of said first portion, said arched part extending radially substantially in the front direction, said third portion being intended to face the medial inferior area of the inguinal anatomy. Fig. 1