A proved way to improve the quality of the rehabilitation treatment and to reduce the time spent for recovery is the use of the biofeedback theory. In the present project it was designed a biofeedback system, implemented in Visual C++ 6.0®, to improve the adult transfemoral amputee gait. For these purpose, we took kinetic, and kinematic data from transfemoral amputees, that was digital processed involving interpolation, filtering and decimation, and then compared with healthy gait data to determine the difference between data measured by the system and the movement desired, that difference was presented as a feedback stimulus for the movement of the joints of the legs during gait on a treadmill. The biofeedback stimulus were displayed in "real time" and give the signal to favor a normal gait pattern, following the biofeedback system is possible to train a new functional gait, fist during the therapy and later in the everyday living.