The objectives of this study were to investigate the effects of thoracic flexibility exercise on chest function and mobility and to provide the information of physical therapy for patients with idiopathic scoliosis. Forty female subjects who were diagnosed with scoliosis participated in this study and were divided into the experimental and control groups. The experimental group consisted of 20 patients who were treated with thoracic flexibility exercise program during the admission (10 days) ad one month after discharge. The control group consisted of 20 patients who were not treated with thoracic flexibility exercise program. Vital capacity was measured using a respirometer. The chest expansion were calculated using differences of chest circumference between maximum inspiration and maximum expiration measured under armpits, at the junction between the sternum and xyphoid process, and at the waist. All subjects were measured two times: before the admission and at one month after discharge. Data were compared by groups using independent t-test, Vital capacity and chest expansion values (the armpit, chest and waist values) were significantly higher for the experimental group compared to those of the control group (p<.05). The findings of this study show that thoracic flexibility exercise program can lead to an increase in vital capacity and chest expansion and has a positive effects in relieving symptoms and restoring thoracic mobility.