An articulating spinal disc prosthesis is provided including a first upper member for engagement with an inferior surface of a first vertebra in use and a second lower member for engagement with a superior surface of a second vertebra in use. The first upper member has a vertebra contacting surface and a convex bearing surface provided on an opposite surface thereof. The second lower member has a vertebra contacting surface and a concave bearing surface provided on an opposite surface thereof. The convex bearing surface of the first upper member engages with the concave bearing surface of the second lower member in use and the concave bearing surface of the second lower member includes an inclined ramp to allow rotation and inclined translation in use.