Synovial cysts most commonly involve the joints of the extremities. These cysts are rarely found in the spinal canal or the vertebral facet joints. However, if manifested as such, they can pose serious diagnostic and therapeutic problems due to the presentation, which most often resembles nerve root or spinal cord compression. Acute low back pain and radiculopathy are often attributed to a herniated nucleus pulposus. This paper presents a case of synovial cyst in a 62-year-old woman with a 2-year history of refractory low back pain with distal radiation. A facet joint cyst was encountered upon neuroimaging, resulting in excision of the cyst. In this report, we discuss the differential diagnosis of synovial cysts, the role of computed tomography and magnetic resonance imaging in the diagnosis, and treatment options for this uncommon entity.