Postoperative pain, arising due to surgical tissue injury, is most frequent type of pain found in clinical practice. In postoperative analgesia opioids still constitute the fundamental form of pain treatment, but the development of neurophysiology and neuropharmacology has allowed for the optimization of postoperative analgesia. Therefore, in order to potentialize the pain relief effect of opioids and/or inhibit the nociception process and its consequences, diverse drugs and therapies are used. The procedure is called multimodal analgesia and consists in the administration of opioids in conjunction with NMDA antagonists, COX inhibitors, cholecystokinin antagonists, agonists of muscarine receptors, agonists of alpha-2 receptors or cytokine inhibitors. An alternative or supplementary therapy in the postoperative period relies on local anaesthetic techniques or TENS. There also exists pre-emptive analgesia, whose aim is to safeguard the central nervous system from increased afferent nociceptive stimulation during the operation.