BACKGROUND: Local anaesthetics may alleviate pain more effectively than any other anaesthetic method. In regional anaesthesia/analgesia, rare but serious complications make it necessary to always consider the risk-benefit ratio. The article discusses these issues and gives advice on effective and safe conduct. MATERIAL AND METHODS: The article is based on non-systematic literature searches in the PubMed and Cochrane databases and our own experience from research and clinical work. RESULTS: Regional anaesthesia is obtained by administering local anaesthetics near the spinal cord and nerve roots (spinal, epidural), spinal nerves (paravertebral), or close to peripheral nerves. Parts of the body will then become numb and paralysed. The same techniques are used for regional analgesia, but this is obtained by using more dilute solutions of local anaesthetics, and other analgesic drugs are often added. Pain impulses are inhibited, but sensation of touch and muscle functions are intact. Regional analgesia gives superior relief of pain provoked by movement. This facilitates early postoperative mobilization of patients, even after major surgery in weak patients. For these patients optimally performed regional analgesia may reduce postoperative morbidity and mortality better than general anaesthesia and opioid and non-opioid analgesics administered postoperatively. Infiltration of the wound with local anaesthetics followed by optimally dosed non-opioid and opioid analgesics is a good alternative for some types of surgery. The risk of spinal bleeding has increased due to increased patient age, routine thromboprophylaxis and frequent use of antihaemostatic drugs, including platelet inhibitors. Infections in the spinal cord are caused by insufficient hygiene. Selection of patients who are likely to benefit from regional anaesthesia/analgesia, strict hygienic precautions, optimal technique, close monitoring, and assistance from an acute pain team, as well as hospital protocols for handling rare but serious complications, have reduced the occurrence and consequences of serious complications. INTERPRETATION: Optimal regional anaesthesia/analgesia may improve the postoperative result.