Recent developments in blockade techniques are based on the possibilities offered by modern sonography. With high frequency linear probes, the smallest tissue structures, such as peripheral nerves, in areas close to the surface can be visualised. This is the prerequisite for ultrasound-guided blockade techniques which has now been established for available peripheral blockades. These techniques are basically far superior to all other assist methods of peripheral blockades, because they allow a success rate close to 100%, a short preparation time and a reduction in the use of local anaesthetic agents. Apart from these, one particularly important aspect is that they reduce the risks of local anaesthesia procedures by direct imaging of neighbouring anatomical structures. In this article the theoretical basis of ultrasound techniques and their practical use in local anaesthesia will be presented.