Today the most common application in the field of computer-assisted surgery is navigated total knee arthroplasty. During the last 5 years the imageless kinematic navigation systems have gained wide acceptance. As several prospective randomized studies could show, the standard deviation of the mechanical axis is reduced significantly by these techniques. However, the direction of the mechanical axis is only one factor which influences the long-term results of total knee arthroplasty. Further important factors are ligament balancing and position of the femoral and tibial components in all three planes. Up to now no studies have been able to show a significantly better functional result, a more rapid recovery, or a decreased complication rate. Drawbacks of the navigation systems are the additional costs and the additional operation time between 15 and 20 min. Therefore, navigated total knee arthroplasty is not yet a standard procedure, but this technique is well on the way to becoming the gold standard in the future.