Subarachnoid-pleural fistula is a well-described complication after anterior surgery for thoracic disc herniation, but is difficult to treat by means of traditional chest and lumbar drains due to interference by positive ventilation pressures that may keep the fistula open and prevent proper closure. Current treatment strategies include surgical repair, which is technically challenging, and noninvasive positive pressure ventilation, which can take several weeks to be effective. In this report, the authors describe a novel treatment for subarachnoid-pleural fistula using percutaneous obliteration with Onyx. Surgery for removal of a T7-8 disc herniation associated with ossification of the posterior longitudinal ligament was performed in a 56-year-old woman via an anterior transthoracic transpleural approach. Ten days after surgery, she presented with diplopia due to a subarachnoid-pleural fistula that was confirmed by CT myelography. Percutaneous injection of Onyx was performed under local anesthesia. Postprocedure CT showed complete obliteration of the fistula with no adverse events. A CT scan obtained 1 month later showed complete resolution of the pleural effusion. Neurological examination at 3 months postsurgery was normal. Clinical and radiological follow-up at 1 year showed complete recovery and no sign of fistula recurrence. Percutaneous treatment for subarachnoid-pleural fistula is an easy, safe, and effective strategy and can therefore be proposed as a first-line option for this challenging complication.