The study was an exploratory, one group pretest/post-test study, with the objective of investigating the short-term effects of thoracic spine thrust manipulations (TSTMs) on patients with shoulder impingement syndrome (SIS). There is evidence that manual physical therapy that includes TSTM and non-thrust manipulation and exercise is effective for the treatment of patients with SIS. However, the relative contributions of specific manual therapy interventions are not known. To date, no published studies address the short-term effects of TSTM in the treatment of SIS. Fifty-six patients (40 males, 16 females; mean age 31.2+/-8.9) with SIS underwent a standardized shoulder examination, immediately followed by TSTM techniques. Outcomes measured were the Numeric Pain and Rating Scale (NPRS) and the Shoulder Pain and Disability Index (SPADI), all collected at baseline and at a 48-h follow-up period. Additionally, the Global Rating of Change Scale (GRCS) was collected at 48-h follow-up to measure patient perceived change. At 48-h follow-up, the NPRS change scores for Neer impingement sign, Hawkins impingement sign, resisted empty can, resisted external rotation, resisted internal rotation, and active abduction were all statistically significant (p<0.01). The reduction in the SPADI score was also statistically significant (p<0.001) and the mean GRCS score=1.4+/-2.5. In conclusion, TSTM provided a statistically significant decrease in self reported pain measures and disability in patients with SIS at 48-h follow-up.