The rectus sheath block (RSB) is a regional anaesthesia technique used for postoperative analgesia following midline abdominal surgeries. It targets the terminal branches of the intercostal nerves (T7–T11), subcostal nerve (T12), and iliohypogastric nerve (L1), which penetrate the posterior rectus sheath to supply the anterior abdominal wall. The block is performed by injecting local anaesthetic between the rectus abdominis muscle and the posterior rectus sheath, allowing cephalocaudal spread within the compartment. Ultrasound guidance enhances safety and precision by identifying the rectus muscle, posterior sheath, and epigastric vessels, minimizing risks such as vascular puncture, bowel injury, and haematoma. RSB provides effective opioid-sparing analgesia and is a viable alternative when epidural anaesthesia is contraindicated. Continuous catheter techniques enable prolonged pain relief, improving postoperative recovery.