Objective: We performed a retrospective patient chart review to determine the feasibility and safety of en bloc resection of lamina and ossified ligamentum flavum in the treatment of thoracic ossification of ligamentum flavum (OLF).Methods: From January 2000 to June 2006, 36 patients with thoracic OLF underwent en bloc resection of lamina and ossified ligamentum flavum by a burr grinding technique.The range of resection included one lamina superior and one lamina inferior to the diseased segments.Ossified dura mater was removed if present, and simultaneous repair was carried out.Results: The mean preoperative Japanese Orthopedic Association (JOA) score (an evaluation system for thoracic myelopathy with a total score of 11 points) was 5 points, (range 3 to 9 points).The mean JOA score at the last follow-up visit (mean follow-up period 3.9 years) was 8.44 points, (range 6 to 11 points).The range of improvement was from 2 to 6 points, and the mean improvement rate was 60.5% (range 33.3% to 100%).No postoperative aggravation of neurological dysfunction, leakage of cerebrospinal fluid (CSF), wound infection, kyphosis, or recurrence occurred.A CSF cyst found in one patient 3 weeks post-operatively was absorbed automatically after 10 months.Conclusions: The en bloc resection technique described here is both safe and effective.