Pneumocephalus resulting from a subarachnoid-pleural fistula following resection of a pulmonary neoplasm is a very rare postoperative complication: we have found only 17 cases in the literature. We report the case of a 65-year-old man diagnosed with a superior sulcus tumor who underwent a left upper lobectomy and costal resection following neoadjuvant radiation therapy. Soon after surgery, the patient developed a subarachnoid-pleural fistula and pneumocephalus that required reoperation and drainage. Recurrence was suspected when chronic aseptic meningitis developed. Another thoracotomy was required to resolve the complication.