Since the 1960s, intraoperative administration of opioids is considered a keystone of anaesthesia as well as hypnotics and muscle relaxants. Since then, anaesthesia has changed from inhalation to multimodal anaesthesia with lower doses of hypnotic. In 2018, the intraoperative objectives of hypnosis, haemodynamic stability, immobility and anticipation of postoperative analgesia can be achieved without opioids. Moreover, opioid administration consequences are neither scarce nor benign for the patient. Perioperative opioids are associated with nausea and vomiting, sedation, ileus, confusion/delirium, respiratory depression, increased postoperative pain and morphine consumption, immunodepression, hyperalgesia and chronic postoperative pain. Among these complications, hypoxemia, ileus and confusion/delirium are the most frequent. Opioid-free anaesthesia (OFA) is based on the idea that haemodynamic stability can be achieved without opioids during anaesthesia. OFA is multimodal anaesthesia associating hypnotics, NMDA antagonists, local anaesthetics, anti-inflammatory drugs and alpha-2 agonists (Dexmedetomidine). The first studies on the benefit of OFA reported a significant postoperative morphine sparing, decreased pain and reduction of postoperative nausea and vomiting. However, proofs of the effect of OFA on reducing opioid-related adverse effects surgery are still scarce and more studies are needed.