Erythema elevatum diutinurum is a relatively rare disease of unknciwr etiology. It is charaterized by persistent erythematous plaque and nodule that are usually affected symmetrically over extensor surface of extremities. Our patient, a 16-year-old female was referred for evaluation of asy nptomatic papules and nodules on extensor aspects of the hands, legs and buttocks. She complained of arthralgia on the knees. The laboratory values were all within normal limits with the exception of slight elevation of white blood cell counts and erythrocyte sedimenation rate. A skin biopsy specimen we obtained from the nodular lesion of the leg that showed preclominantly perivascular neutrophilic influration with occasional lymphocytes and unclear dusts. She was treated with 75mg/day of dapsone. Shin lesions were much improved after ten days. Eight weeks later, the lesion had almost resolved. After the discontinuation of dapsone, new lesions developed on the legs. Retreatment with dapsone resulted it a dramatic response of her lesions after three weeks. (Kor, J Dermatol 1993;31(6): 968-972)