Two large nerve trunks are responsible for supplying the legs: the femoral nerve, the obturator nerve and the lateral femoral cutaneous nerve arising from the lumbar plexus and the sciatic nerve and the posterior femoral cutaneous nerve from the sacral plexus. Thus, it is always necessary to block both nerve trunks to achieve complete anaesthesia of the leg. There are various ways to access the branches of the lumbar plexus and to the sciatic nerve that we will discuss in the following.