Skeletal maturity in 86 girls with adolescent idiopathic scoliosis was determined by assessing their bone age at the hand and wrist and by the development of their iliac (Risser's sign) and ischial apophyses.The two methods were compared and a statistically significant correlation was noted, signifying that the development of the iliac and ischial apophyses is a sensitive parameter for assessing skeletal maturity in these patients.The iliac apophysis is visible on routine follow-up radiographs of these patients, so using this criterion results in a reduction of roentgen ray exposure to the patient and significant financial savings. A more sensitive method of assessing the development of the iliac and ischial apophyses is suggested.