SUMMARY. Identical twin boys with palmoplantar keratoderma were treated by total excision of the skin of one sole to the level of the plantar aponeurosis, followed by grafting. The hyperkeratosis did not recur on the treated sole, and the keratoderma of the untreated soles and of the palms disappeared. In both cases the keratoderma eventually recurred on the palms and on the untreated sole.