Thoracic disc herniation (TDH) surgery carries risks of neurological worsening due to thoracic cord retraction injury. Multiple approaches have been developed aiming for resetting the disc herniations of the thoracic segment. We have conducted a prospective observational study to evaluate the mid-term outcome of thoracic microdiscectomy with bilateral decompression via a unilateral approach (BDUA). Patients were checked pre-operative, post-operative, and late follow-up by Oswestry Disability Index (ODI), Visual Analogue Scale (VAS), and radiological images. Twenty-three patients were treated for TDH by microdiscectomy with BDUA between January 2010 and January 2015. Nine patients were female, fourteen were male, and all of those mean age was 51,2 +/- 8,3 (range 29-64 years). The mean follow-up time was 22,04 +/- 8,59 months (range 13-58 m). The ODI and VAS scores decreased significantly in both postoperative and late follow-up evaluations. Microdiscectomy with BDUA for thoracic disc herniations allowed sufficient and safe decompression of the neural structures and resulted in a significant reduction of symptoms and disability. (C) 2018 Elsevier Ltd. All rights reserved.