A temporo-mandibular joint prosthesis comprising: a first part (2) for attaching to a temporal bone a second part (1)for attaching to a mandible bone and a mechanism linking the first part and the second part. The mechanism defines a range of motion of the first part relative to the second part for when the first and second parts are attached to a temporal bone and a mandible bone, respectively. The mechanism includes a rotary joint (14) providing a rotational range of motion of the first part relative to the second part and a first slider joint (22) providing a first translational range of motion of the first part relative to the second part.