Sciatic nerve block is considered difficult to perform, but very useful for lower limb anaesthesia and analgesia. The use of a nerve stimulator makes the technique easier. Functionally, it is better to consider that there are three independent sciatic nerves, namely, the posterior cutaneous nerve, the tibial nerve and the common peroneal nerve. Searching for blocking these three nerves and especially the latter two, specifically improve the reliability and quality of blockade.