['Hand dominance has been reported to be an important factor affecting outcomes after upper extremity trauma but remains unstudied after hemiarthroplasty for fracture. This study determined whether dominance affected outcomes after hemiarthroplasty for proximal humerus fractures.', 'Retrospective cohort study.', 'Tertiary care referral center.', 'Sixty-one patients, after hemiarthroplasty for proximal humerus fracture, returned for comprehensive assessment and were divided into 2 groups: dominant (DOM) shoulder affected (n = 25) and non-dominant (non-DOM) shoulder affected (n = 36).', 'Fracture-specific proximal humeral hemiarthroplasty for displaced proximal humerus fractures.', 'Patients were assessed with self-reported outcomes (visual analog scale pain, American Shoulder and Elbow Surgeons shoulder score, disability of the arm, shoulder, and hand questionnaire, simple shoulder test, and short form 12) and objective (range-of-motion and hand-held dynamometer strength) testing.', 'At 49 months of mean follow-up, there were no significant differences between groups for gender, age, follow-up time, or visual analog scale pain (P > 0.256). The DOM-affected group had significantly worse scores for American Shoulder and Elbow Surgeons shoulder score (P = 0.043), disability of the arm, shoulder, and hand questionnaire (P = 0.039), and simple shoulder test (P = 0.021). The DOM-affected group also had consistently higher correlations between self-reported and objective outcomes than the non-DOM group.'] Do outcomes After Hemiarthroplasty for Proximal Humerus Fracture Are Significantly Affected by Hand Dominance?