We make a clinical and bibliographical review in diagnosis and treatment of Histiocytosis X, who includes three components: Eosinophylic granuloma, Hand-Schüller-Christian disease and Letterer-Siwe syndrome. We had 28 cases, with an average age of 11.8 years. Eighteen (64%) were males and 10 (36%) females. Seventeen were solitary lesions and 8 had multiple skeletal lesions. Three patients had generalized disease: 2 with Hand-Schüller-Christian disease and 1 with Letterer-Siwe syndrome. The femur lesion was frequently observed among the solitary lesions and the cranium involvement in the multiple skeletal lesions. The total number of lesions was 47. The treatment depended on the location, the clinical manifestations and the number of lesions. The patients with solitary lesions (17) were treated with curettage and bone grafting in 6 cases, segmental resection in 3 cases, only curettage in 3, radiotherapy in one and 4 patients didn't receive treatment. The patients with multiple lesions (8), were treated surgically (4 cases), only radiation therapy (2 patients), with surgery and radiotherapy (1) and one patient had no treatment. The generalized disease was treated with surgery of the main lesion depending in the clinical manifestations and chemotherapy and radiotherapy. The prognosis was good in almost all the patients and we observed regression of the disease even without specific treatment. The case of acute generalized disease died due to systemic complications.