Refsum disease is a genetic progressive neurological disorder caused by neurotoxic phytanic acid, a nutritional component patients are unable to metabolize. Symptoms include retinopathy, polyneuropathy, ataxia, and deafness. They are variable and rarely recognized before adulthood. The authors report the case of a 14-year-old girl diagnosed because of night blindness. They treated her with a phytanic acid-poor diet and extracorporeal lipid apheresis. They used different methods over a 30-month period. Thereafter, the patient was treated with diet only. Membrane filtration and heparin-induced extracorporeal low-density lipoprotein precipitation apheresis were well tolerated. Withdrawal of phytanic acid was studied quantitatively. During a 5-year period, blood phytanic acid levels decreased to a noncritical range. The patient remained free of ophthalmological and neurological progression for a total observation of 12 years. Early diagnosis and effective measures to keep the phytanic acid load low can probably prevent the serious sequelae of Refsum disease. Developing a method for newborn screening is desirable.