Process for pre-surgical, automatic and personalized modelling and bending of a surgical prosthesis for use in the correction of pectus excavatum comprising the following steps: a) segmenting from 3D medical images of a patient, the structures comprising the ribs and the sternum based on anatomo-surgical references; b) automatically detecting the point of largest deflection of the sternum based on 3D coordinates of the points from the sternum; c) defining the limit box where the intercostal space is located by: defining a plane that includes the point of largest deflection of the sternum and is perpendicular to the sternum; creating a cuboid with one of the bases abutting on the defined plane and having height equal to the width of the prosthesis; defining the intercostal space through the points of the ribs interior to the cuboid; d) automatic correction of the sternum elevation to a position predicted for the correction of pectus excavatum, given by the correction factor of the sternum obtained from the most anterior point of the ribs belonging to the intercostal space, having this position the possibility of later manual modification by the user; e) virtual and personalized modelling of the surgical prosthesis and selection of the most appropriate standard size of the prosthesis to be applied in the patient, based on the position defined for the sternum; f) positioning and visualizing the virtual surgical prosthesis modelled from the point of largest deflection and final position of the sternum; g) graphical simulation of the pre-operative expected cosmetic result of the thoracic wall after placement of the surgical prosthesis in the patient; h) bending of the surgical prosthesis, according to the virtual model, with real-time monitoring and control of the mechanical behavior of the surgical prosthesis material. a) segmenting from 3D medical images of a patient, the structures comprising the ribs and the sternum based on anatomo-surgical references; b) automatically detecting the point of largest deflection of the sternum based on 3D coordinates of the points from the sternum; c) defining the limit box where the intercostal space is located by: defining a plane that includes the point of largest deflection of the sternum and is perpendicular to the sternum; creating a cuboid with one of the bases abutting on the defined plane and having height equal to the width of the prosthesis; defining the intercostal space through the points of the ribs interior to the cuboid; d) automatic correction of the sternum elevation to a position predicted for the correction of pectus excavatum, given by the correction factor of the sternum obtained from the most anterior point of the ribs belonging to the intercostal space, having this position the possibility of later manual modification by the user; e) virtual and personalized modelling of the surgical prosthesis and selection of the most appropriate standard size of the prosthesis to be applied in the patient, based on the position defined for the sternum; f) positioning and visualizing the virtual surgical prosthesis modelled from the point of largest deflection and final position of the sternum; g) graphical simulation of the pre-operative expected cosmetic result of the thoracic wall after placement of the surgical prosthesis in the patient; h) bending of the surgical prosthesis, according to the virtual model, with real-time monitoring and control of the mechanical behavior of the surgical prosthesis material.