With the development of powerful computer systems, computer-assisted medical diagnosis and therapy have become common over the last 10 years. Even in the surgical field, computer- and robotic-assisted techniques are becoming practical but are not yet used on a daily basis. In the orthopaedic field, computer and robotic assistance is used in planning and performing demanding three-dimensional osteotomies, setting pedicle screws in the spine and milling the femoral medullary canal in total hip replacement. This article introduces a computer- and robotic-assisted system for performing arthroplasty in total knee replacement procedures.