The authors describe a case of an 80-year-old man with a gradual weakness of the lower extremities not linked to any known traumatic episode over the 2 weeks before admission. CT scan and MRI of the spine revealed a cystic formation, measuring about 1cm in diameter, at C7-T1 at the left posterolateral site at the level of the articular facet. During surgery, the mass appeared to be in the ligamentum flavum at the level of the articular facet and was in contact with the dura mater. After the removal of the mass, there was an immediate and significant improvement of the patient's symptoms. Histopathologic examination showed the cyst to be composed of nonspecific degenerative fibrous tissue with mild inflammatory change and confirmed the cyst as a synovial cyst. Synovial cyst in the cervical region is a very rare lesion causing myelopathy. Surgical removal of the cyst and decompression of the spinal cord results in good neurological recovery.