[Purpose] The purpose of this study was to investigate the effects of thoracic spinal manipulation therapy on respiratory function including forced vital capacity and forced expiratory volume in one second in young healthy individuals. [Subjects and Methods] Thirty young healthy subjects recruited from a local university participated in this study. Subjects were randomly allocated into an experimental group (n=15) and a control group (n=15). The experimental group received thoracic spinal manipulation and the control group received placebo thoracic spinal manipulation. Respiratory function tests, including forced vital capacity and forced expiratory volume in one second, were measured before and after intervention. [Results] The values for both tests were significantly higher in the experimental group. The control group showed no changes after the intervention. Differences in pre- and post-intervention values for both tests were significantly different between the 2 groups. [Conclusion] Spinal manipulation therapy applied to the thoracic region improved respiratory function test results of participants in this study.