Hip prosthesis (100; 200) comprising: - a stem intended to be inserted in a neck of a femur, - a prosthetic head shaped as a substantially hemispherical cup, intended to be inserted in an acetabular seat, said prosthetic head comprising through holes to receive fixing screws intended to be fixed to said acetabular seat, - a distal prosthetic component connected to the stem and shaped as a substantially hemispherical cup with concavity towards the concavity of said prosthetic head, said distal prosthetic component having a border, - a ball disposed between said distal prosthetic component and said prosthetic head in such manner to generate a ball coupling, said prosthetic head comprises: - a central portion (40; 240) with a higher thickness than a peripheral portion of the prosthetic head, in such manner to generate a step (42; 242) inside the prosthetic head, said central portion (40; 240) of the prosthetic head being engaged on the external surface of the ball in such manner to generate an empty space between the external surface of the ball and the internal surface of the peripheral portion of the prosthetic head, so that the border of said distal component is introduced in said empty space, characterized in that said prosthetic head further comprises: - grooves obtained on the external surface of said prosthetic head to allow for anchoring the prosthetic head to the acetabular seat in order to obtain a primary stability of the prosthetic head, wherein said through holes are exclusively obtained in said central portion (40; 240) of the prosthetic head and said grooves are exclusively obtained in said peripheral portion of the prosthetic head. - a stem intended to be inserted in a neck of a femur, - a prosthetic head shaped as a substantially hemispherical cup, intended to be inserted in an acetabular seat, said prosthetic head comprising through holes to receive fixing screws intended to be fixed to said acetabular seat, - a distal prosthetic component connected to the stem and shaped as a substantially hemispherical cup with concavity towards the concavity of said prosthetic head, said distal prosthetic component having a border, - a ball disposed between said distal prosthetic component and said prosthetic head in such manner to generate a ball coupling, - a central portion (40; 240) with a higher thickness than a peripheral portion of the prosthetic head, in such manner to generate a step (42; 242) inside the prosthetic head, said central portion (40; 240) of the prosthetic head being engaged on the external surface of the ball in such manner to generate an empty space between the external surface of the ball and the internal surface of the peripheral portion of the prosthetic head, so that the border of said distal component is introduced in said empty space, characterized in that said prosthetic head further comprises: - grooves obtained on the external surface of said prosthetic head to allow for anchoring the prosthetic head to the acetabular seat in order to obtain a primary stability of the prosthetic head, wherein said through holes are exclusively obtained in said central portion (40; 240) of the prosthetic head and said grooves are exclusively obtained in said peripheral portion of the prosthetic head. - grooves obtained on the external surface of said prosthetic head to allow for anchoring the prosthetic head to the acetabular seat in order to obtain a primary stability of the prosthetic head,