OBJECTIVE The role of conventional radiography and bone scintigraphy in predicting the outcome of Legg-Calvé-Perthes disease was investigated. METHODS The 75 children reviewed (86 hips) were followed up to the primary healing of the disease. The findings at conventional radiography (obtained at presentation, at the time of maximum capital head involvement, and at the end of the healing process of the disease) were compared to early bone scintigraphy features. CONCLUSIONS Bone scintigraphy provided more accurate information concerning the extent of the necrotic process than initial radiographs. Moreover it could determine revascularization and consequently the stage of the disease. The methods was, however, unable to predict the outcome of the disease in some cases, particularly if it was performed late after the onset of symptoms. Conventional radiography provided important information about other parameters such as "head-at-risk" signs which facilitated treatment selection. Of these signs not only lateral subluxation but also metaphyseal changes strongly predispose to severe deformity of the hip joint.