Diabetic neuropathic cachexia (DNC) is one of the rarest presentations of diabetic neuropathy associated with profound weight loss. A 50-year-old Korean woman with poorly controlled type 2 diabetes complained of intractable pain in the trunk and lower extremities, and total body weight loss of 17% over a 6 month period. The patient's symptoms persisted after glucose control and various medications for neuropathic pain. A diagnosis of DNC was made based on the rapid onset of severe pain, polyneuropathy, and marked weight loss without evidence of end organ disease other than mild retinopathy, and the exclusion of other possible causes. Spontaneous improvement of the patient's neuropathic pain and gradual weight gain occurred after 6 months of supportive care. Since the original report of DNC, 31 cases have been published in the English-language literature; however, ours is the first reported case in Korea. Clinicians must be aware of this debilitating complication of diabetes because of its severity and rapid progression.