Pneumocephalus as a complication of anterior lumbar spinal surgery is extremely rare. A 53-year-old male patient presented with L4 fracture. Posterior fixation from L3 to L5 was conducted one day after the trauma. As the patient’s neurological deficit persisted, additional anterior surgery by L4 vertebral body replacement was performed on the 19th day. Both surgeries were completed without obvious intraoperative complications. Two weeks after the anterior lumbar surgery, the patient complained of severe headaches, and computed tomography scan revealed pneumocephalus and massive fluid retention in the abdomen. The symptoms improved with conservative treatment, including bed rest, spinal drainage, intravenous drip infusion, and prophylactic administration of antibiotics. Due to the lack of tamponade effect in the soft tissues, a large amount of cerebrospinal fluid leakage may induce and cause progression of pneumocephalus in anterior dural injury.