Spinal cord compression due to synovial facet cyst in thoracolumbar spine is rare. Several etiologies of juxtafacet cysts (JFCs) in this location have been discussed, particularly overload of the arthritic facet joints.Due to the narrow caliber of the thoracic spine, JFC in this location can present with radicular pain or progressive myelopathy. We report an interesting case of a 67 year-old woman who presented with the signs and symptoms of thoracic myelopathy. A left-sided T11/12 JFC was identified on MRI and CT scans correlating with her myelopathy. She experienced a substantial improvement in her myelopathic symptoms after surgical excision of the JFC. The presentation, etiology, and therapeutic aspects of JFC are discussed in detail.