<p>Sleep architecture is frequently disrupted after major surgery, leading to acute and chronic postoperative sleep disorders that may contribute to episodic hypoxia, hemodynamic instability, postoperative fatigue, cognitive dysfunction, depression. These all have potentially detrimental impacts on disease regression. Pain is a key driver of postoperative sleep disruption and opioids are widely used for pain management due to their potent analgesic and sedative effects. Opioids are conventionally believed to induce natural sleep and reduce sleep disorders. However, available evidence suggests that opioids can disrupt sleep architecture, leading to sleep deprivation, fragmentation and restriction. This systematic review investigates the detrimental effects of opioids on postoperative sleep and explores the underlying mechanisms responsible for sleep disorders. By synthesizing current evidence wehighlight the risks associated with opioid-centric pain management strategies and advocate for a more balanced approach that optimizes pain relief while mitigating opioid-induced sleep disruption.</p>