Cerebrotendinous xanthomatosis is a rare hereditary lipid storage disease characterised by deposits of cholestanol. In a female patient with bilateral swelling of the Achilles tendon who underwent biopsy, cerebrotendinous xanthomatosis was confirmed by combining disease patterns. She suffered from ataxia, depression, epilepsy, reduced intelligence, bilateral cataracts, gallstones, and atherosclerosis. Concentration of serum cholestanol was 10 times higher than normal. As causal therapy, ursodeoxycholic acid and statin drugs were prescribed to halt progression.