OBJECTIVE: To investigate the effects of a corrective functional exercise program on postural thoracic kyphosis in teenagers in China. DESIGN: A single-blind randomized controlled trial including students with a thoracic kyphosis angle (TKA) >40 degrees measured using the SpinalMouse. SETTING: China Institute of Sport Science and three middle schools in Beijing, China. SUBJECTS: A total of 181 subjects were included in this trial; of these, 164 subjects were included in the analyses (intervention group, n = 81; control group, n = 83). INTERVENTION: The intervention group received a functional exercise program designed to correct postural thoracic kyphosis, and the control group received an exercise program designed in accordance with the state-regulated curriculum. MAIN MEASURES: The primary outcome variable was TKA. Secondary outcome variables were lumbar lordosis angle (LLA), sacral angle (SA), and incline angle (INA) measured in the upright position; thoracic, lumbar, and sacral spine range of motion (ROM) and INA ROM (change in center of gravity) measured in the forward bending and extended positions; and changes in TKA, LLA, SA, and INA measured during the Matthiass test. RESULTS: There were significant differences in pretest and posttest TKA in both groups (intervention group: pretest 47.09 +/- 5.45, posttest 38.31 +/- 9.18, P < 0.0001; control group: pretest 47.47 +/- 6.06, posttest 43.59 +/- 7.49, P < 0.0001). After adjustment for gender and pretest values, there were significant differences in posttest TKA, change in SA, and thoracic ROM in the intervention group compared to the control group ( P < 0.05). CONCLUSION: The corrective functional exercise program designed for this study improved exaggerated thoracic kyphosis in teenagers.