A 66 year-old woman was admitted to our hospital for progressive weakness of both lower extremities since a month ago. Imaging study, based on plain X-ray, computed tomography and magnetic resonance image revealed spinal stenosis owing to anterior slipping of T10/11 segment. Degenerative spondylolisthesis is common in the lumbar spine and rarely occurs in the cervical spine. But there was no report of degenerative spondylolisthesis in thoracic spine. The authors experienced a case of degenerative spondylolisthesis in the thoracic spine. And we achieved a satisfactory result with posterior decompressive laminectomy alone.