We report a 52-year-old female patient in whom all the finger- and toe-nails were rough and turbid. She had been treated as onychomycosis for a long time by the near-by dermatologists. Their treatments had not been effective at all. We diagnosed her nail lesions as twenty-nail dystrophy. She was treated by us with the oral steroid therapy. The nail lesions had been improved soon, and well controlled, by the stcroid therapy.