Ankylosing spondylitis is a challenging disease for anesthesiologist due its airway and axial skeleton involvement. A 55 years old male patient suffering from severe ankylosing spondylitis, admitted to Anesthesiology Clinic. He was planned to receive a midline open ventral hernia repair. We decided to perform bilateral ultrasound-guided erector spinae plane (ESP) block at the level of T8 with 0.4 mcg kg-1 hour-1 dexmedetomidine sedation for complete anesthesia of the surgery. We performed ESP block with 25 mL of 0.25% bupivacaine and repeated the same procedure at the contralateral side. Twenty minutes later, the skin incision was started. We didn't need to apply an additive anesthetic or analgesic drug throughout the surgery. ESP block provides analgesia for different dermatomes by effecting ventral rami and rami communicantes of spinal nerves depending on the level of injection site. When performed between T7-T9 levels, it has been reported to effectively attenuate postoperative pain after different types of surgeries.