Background: Perioperative pain management should be planned preoperatively and based on usage of pharmacological and non-pharmacological modalities as a multimodal analgesia (MMA). Regional anaesthesia has superior advantages than opioid-based anaesthesia and is one of the cornerstones of the Enhanced Recovery After Surgery (ERAS) especially in Patients undergoing spine surgery having already troublesome chronic pain and analgesic use. The present study was carried out to compare erector spinae plane block (ESP) with general anaesthesia versus conventional general anaesthesia in lumbar spine surgery. Materials and Methods: This study was done on thirty adult patients of both sexes scheduled for elective lumbar spine surgery under general anaesthesia. They were randomly categorized into two equal groups (fifteen patients each); ESP was used for group I, and MMA was used for group II. Data was collected on anaesthetic requirements based on entropy monitoring and haemodynamic parameters, stress response measurement based on serum cortisol and blood glucose levels, controlled hypotensive anaesthesia; various drugs required and doses given, intraoperative and postoperative analgesia, postanaesthesia care unit data concerning recovery. Results: The group I (ESP) had statistically significant decrease of the response and the response-state entropy difference levels when compared to the group II (MMA) after stimulus and during the 1st time interval. The incidence of hemodynamic changes was significantly higher in the group I (ESP) than group II (MMA). Only the serum cortisol but not the blood glucose levels had statistically significant lower mean values 4 h postoperatively in group I (ESP) compared to group II (MMA). The patients received ESP had statistically significant lower mean expired isoflurane concentration, decreased emergence time, intraoperative fentanyl consumption and total dose of pethidine given up to 8 hrpostoperatively. Conclusions: Erector spinae plane block (ESP) can be considered safe and effective perioperative analgesic modality for lumbar spine simple decompression surgery. It helps in controlled hypotensive anaesthetic technique and decreases inhalational anaesthetics and intraoperative opioid requirements.