Background: Subacromial impingement syndrome (SIS) is believed to be the most common cause of shoulder pain. Purpose: The aim of this cross-sectional and correlation study was to investigate the relationship between pain, disability, proprioception and functional performance in patients with subacromial impingement syndrome. Subjects and Methods: Twenty- four subjects were included in this study. Their mean age was 26.83± 4.39 and they were referred from orthopedic surgeons with diagnosis of SIS. All subjects were assessed for pain intensity and function using The Arabic Shoulder pain and disability index (SPADI), shoulder proprioception using an inclinometer to calculate the active repositioning error, and functional performance using three functional performance tests (push up, modified pull up, Davies' Closed Kinetic Chain Upper Extremity Stability). A correlation analysis was conducted between the outcome measures using Pearson's correlation coefficient. Results: No significant relationships were found between pain, proprioception, and functional performance (p> 0.05). On the other hand, pain, and disability of SPADI showed significant correlation (p ≤ 0.05). In addition, internal rotation repositioning error showed a significant correlation with push up test, push up significantly correlated with pull up test. Moreover, there was direct significant correlation between push up and CKC tests (p ≤ 0.05). Conclusion: Functional performance of patients with SIS is correlated with the degree of pain and disability and should be considered in the assessment while should joint proprioception does not seem to be correlated with the measured outcome variables.