Introduction: Shoulder overuse injuries can cause pain, limitation of shoulder motion, associated with abnormalities in the head, neck, shoulders and back posture which affect upper extremity's functions. Stretching and strengthening exercises, as an effective way, are recommended to improve scapular position, back, head and shoulder posture in shoulder overuse syndrome. The purpose of this study was to evaluate head and shoulder posture as well as the effect of therapeutic exercises to improve head and shoulder girdle posture, thoracic spine curvature and scapular position in patients with shoulder overuse syndrome.Methods: This is a Quasi-Experimental study, was conducted on 36 eligible patients with shoulder overuse syndrome. Before and after 6-week exercise therapy protocol; scapular protraction, rotation and symmetry, forward shoulder and head posture as well as thoracic spine curvature was measured.Results: The results of this study revealed a significant improvement in scapular protraction, forward head posture and mid thoracic curvature (p<0.0001), but there was no significant differences in scapular rotation and symmetry.Conclusion: Our findings indicate the effectiveness of 6-weeks exercise therapy protocol in improvement of head, shoulder, scapula and mid thoracic posture.