A 51-year-old man with a 1-month history of lower back pain and radiating pain visited to our pain clinic. A magnetic resonance imaging (MRI) scan demonstrated a cyst like mass at the level of the L4-5 interspace and compression of the thecal sac and the nerve root on the right side. We performed percutaneous needle aspiration of the lumbar zygapophyseal joint synovial cyst under fluoroscopic guidance. The patient felt an immediate relief of symptoms after the aspiration, and had no signs or symptoms of recurrence at the follow-up 6 months later. No demonstrable lesion was found in the 6 months follow-up MRI.