Hepatic myelopathy is a rare neurological complication in patients with chronic liver failure and most patients who suffered from this disorder were demonstrated to have portal-systemic shunt. A 31-year-old man who was diagnosed as having adult-onset type II citrullinemia (CTLN2) and had a six-year history of recurrent hepatic encephalopathy showed progressive spastic paraparesis with no involvement of sensation and sphincter function. Examinations of cerebrospinal fluid and spinal MRI were normal. He suddenly died of acute exacerbation of hepatic encephalopathy with severe brain edema. The pathology of the spinal cord disclosed a localized degeneration of both lateral columns, the lesion being more remarkable in the lower segments of the cord. These clinical and pathological findings of hepatic myelopathy have not been noted in the many patients with CTLN2 previously reported, and our patient is unique in developing hepatic myelopathy without porto-caval shunting. Thus, repeated attacks of encephalopathy with hyperammonemia might secondarily have induced the myelopathy in this patient.