Nalon-Ace® and other nonsteroidal anti-inflammatory drugs (NSAID) containing bromvalerylurea (BVU) are sold as over-the-counter (OTC) drugs and are obtainable without prescription in Japan. A 32-year-old womanwas diagnosed as having chronic BVUintoxication due to habitual use ofNalon-Ace®. In addition to cerebellar ataxia and pyramidal signs well known in this condition, she showedan as yet non-described dystonic posture of the neck. Laboratory tests revealed an elevated concentration of serum organic bromide, iron deficiency anemia, and hyperchloremia. Brain magnetic resonance imaging (MRI) revealed definite cerebellar atrophy.Weshould consider the possibility of chronic BVUintoxication in peculiar neurological cases like ours. (Internal Medicine 37: 788-791, 1998)