An 80-year-old woman was admitted to our hospital with acute onset of flaccid paraplegia and sensory and urinary disturbances that developed soon after acute pain in her lower back and leg. Neurological examination revealed, severe flaccid paraplegia, bladder and rectal disturbances and dissociated sensory loss below the level of L1 spinal cord segment. MR imaging with T2 weighted imaging (T2WI) and diffusion weighted imaging (DWI) on day 2 showed hyper signal intensity in the spinal cord at the vertebral level of L1 while initial apparent diffusion coefficient (ADC) showed decreased signal intensity in the lesion. We diagnosed spinal cord infarction, and anticoagulant and neuroprotective agents were administrated. Serial MRI findings revealed that the DWI signal of the lesion attenuated with time, and pseudo-normalization of the ADC occurred approximately 1 month after onset. These findings were similar to those seen in brain infarction. Our patient demonstrated serial MRI changes of spinal cord infarction showing anterior spinal cord syndrome.