Pain at the autologous bone graft site from the posterior-superior iliac spine (PSIS) is severe enough to affect the postoperative ambulation. It adds to the morbidity of the surgical procedure. Inadequate pain management at the graft site not only affects the postoperative recovery but also can lead to chronic pain. We report the use of ultrasound (US)-guided lumbar erector spinae plane block (ESPB), to deliver effective analgesia for this pain. Patients who underwent occipitocervical fusion (OCF) and C1-C2 fusion using PSIS for atlantoaxial dislocation (AAD)/odontoid fracture from January to March 2020 and who received US-guided lumbar ESPB were retrospectively studied. All the necessary data were collected from the inpatient hospital, anesthesia, and the acute pain service records. A total of six patients received lumbar ESPB, of which one received a single shot injection, and the rest five had a catheter placement for postoperative analgesia. The average volume of intraoperative and postoperative bolus was 27(range: 15-30) and 21 (range: 15-30) mL of 0.2% ropivacaine, respectively. All patients achieved a unilateral sensory blockade ranging from L1 to L3 dermatomes. None of our patients had a numerical rating scale of > 4 on movement at any time point during the first 48 hours except in one, in whom only a single shot bolus was given. No complications related to ESPB were noted. All were ambulated on the second postoperative day except one. The average length of hospital stay was 6 (range: 4-10) days. US-guided lumbar ESPB provides excellent analgesia for PSIS bone graft site pain and promotes early ambulation.