A glenoid implant for a shoulder prosthesis is adapted to be implanted in the glenoid of a patient. The glenoid implant includes an articular body for articulating the glenoidal implant with a humeral component. A plate supports the articular body. An anchoring mechanism for anchoring the glenoid implant along an anchoring axis is adapted to be secured to the glenoid. A securing mechanism secures the plate in position relative to the anchoring mechanism and the glenoid. An adjustment mechanism facilitates selectively adjusting the position of the plate, before it is secured in position by the securing mechanism, in rotation about the anchoring axis and in translation transversely relative to the anchoring axis.