A glenoidal implant for a shoulder prosthesis includes an articular body having two opposite faces which are an articulation face suitable for cooperating with an articulation head of a humeral implant, and an anchoring face from which at least one anchoring stud protrudes for an anchoring in the glenoid cavity including a main anchoring stud at least partially covered with a porous or rough surface coating promoting an osseointegration. The main anchoring stud is provided internally with a central hole extending along a central axis of symmetry of the main anchoring stud and provided to allow guiding a trephine.