Sub-acute combined degeneration (SCD) is a rare cause of demyelination of the dorsal and lateral columns of the spinal cord and is a neurological complication due to vitamin B12 deficiency. Revealing forms of SCD without anemia are rare. We report a case of SCD of the spinal cord in a 33-year-old woman without anemia but with a 10-month history of paresthesis and urine imperiosity. Magnetic resonance imaging (MRI) of the spine showed intramedullary hyperintensity seen on T2-weighted images in the posterior column of the cervico-dorsal spinal cord, extending from C1 to D1. A diagnosis of SCD of the spinal cord was considered and confirmed by a low serum cobalamin. The patient was treated with vitamin B12 supplements and showed gradual improvement in her clinical symptoms.