Eosinophilic granuloma of bone is the most common variant of histiocytosis X. Most of the lesions occur in the skull, ribs, spine or long bone and may be single or multiple. The occurrence in a growing epiphysis is extremely rare and only seven cases have been reported in the literature. A 13 year old boy with eosinophilic granuloma occurring in proximal humeral epiphysis was seen at Seoul National University Hospital in Nov. 1984 and was treated with curettage and autogenous bone graft followed by radiotherapy. The patient was followed for 13 months and complete healing was obtained.