In this review on heredopathia atactica polyneuritiformis (Refsum’s syndrome), special emphasis is put on the nutritional and metabolic aspects of the genetically determined disease. In patients afflicted with Refsum’s syndrome, 3,7,11,15-tetramethylhexadecanoic (phytanic) acid is accumulated in the body lipids and in the plasma due to a partial defect in the α-oxidation mechanism. Phytanic acid which is present in the diet itself, is also readily formed in the organism from phytol ubiquitously present in foodstuffs. Biochemical and dietary studies have not yet elucidated whether the neurological symptoms of the disease are caused by high concentrations of phytanic acid or by a deranged metabolism of nerve ti