BACKGROUND: Acute postoperative pain control after lumbar surgery is imperative to minimizing long-term narcotic use and associated adverse sequela. The safety of intrathecal morphine for postoperative pain management in spine surgery has been investigated; however, to date, no studies have investigated the safety of intrathecal fentanyl with a myofascial plane (MP) block in lumbar procedures. OBJECTIVE: To assess the safety profile of intrathecal fentanyl with a MP block administered during lumbar surgery and the subsequent utilization of postoperative intravenous opioids. METHODS: An intraoperative intrathecal injection of fentanyl and a MP block was administered in 40 patients undergoing open lumbar reconstructive surgery. The procedure performed was an open decompression with lumbar total joint reconstruction at 1 to 3 lumbar levels. Postoperative complications including urinary retention, respiratory depression, and need for IV opioid use were recorded. RESULTS: Postoperatively, none of the study patients required IV opioid medication for supplemental pain control. Thirty-six patients (85%) were discharged same day or before 23 hours postoperatively. No intrathecal fentanyl-related perioperative complications were noted. None of the 40 listed patients experienced urinary retention or delayed respiratory depression. One patient (2%) experienced orthostatic hypotension at postoperative day 1, which resolved on discontinuation of oral oxycodone. CONCLUSION: Intrathecal fentanyl and MP block may be a safe option for perioperative pain control and may reduce the need for supplemental intravenous opioids without increased risk of respiratory depression, urinary retention, or other side effects. Further studies are necessary to compare the efficacy of intrathecal fentanyl with other analgesia techniques.