A 52-year-old male presented with calcification of the cervical ligamentum flavum manifesting as hypesthesia of the bilateral middle, ring, and little fingers and ulnar halves of both forearms, as well as motor weakness in the bilateral upper extremities and gait disturbance. Cervical x-ray tomography detected a round calcified mass on the posterior wall of the cervical canal at the C-5 level. Computed tomography showed the round, nodular calcified mass more clearly. Magnetic resonance imaging showed an epidural low intensity mass compressing and distorting the cervical cord at the C-5 level on both T₁- and T₂-weighted images. Administration of gadolinium-diethylenetriaminepenta-acetic acid caused marginal enhancement of the mass. The lesion was eventually removed by posterior laminectomy. The mass was composed of a very hard crystal-like calcified deposition in the ligamentum flavum. X-ray diffraction analysis of the histological specimen showed calcium pyrophosphate dihydrate (CPPD) and hydroxyapatite in the crystal-like substance, confirming that CPPD is responsible for calcification of the cervical ligamentum flavum.