The invention relates to a knee joint prosthesis comprising a femur part and a tibia part. The plane of the joint gap between said parts is inclined relative to the vertical axis extending from the center of the hip to the ankle according to the anatomical characteristics of the natural joint. According to the invention, at least the tibia part (9) is provided with a recess (19) for accommodating the anterior cruciate ligament. Said recess preferably encompasses a plate sector (20) that is formed within a plate (11) of the tibia part (9), which forms the tibia plateau.