A leg prosthesis wherein the prosthesis shaft and the transtibial part are connected by a prosthesis shaft adapter. The prosthesis shaft adapter is constructed as a compact one-part component with a liner (sleeve as inner prosthesis shaft adapter) of the amputation stump and with a rearward extension for the prosthesis receptacle connection. The prosthesis shaft adapter is designed such that, in addition to the rearward extension of 1 cm to 10 cm, the prosthesis receptacle connection is also angled and laterally offset. Advantageously, the leg prosthesis according to the invention has a relatively low weight due to the prosthesis shaft adapter as a connecting element. The leg prosthesis operates absolutely safely and can be efficiently produced. The fabrication of a leg prosthesis with an individual biomechanical fit to the patient is significantly facilitated, which also results in fewer faulty prostheses.