HYPOTHESIS: Functional outcome after conservative management is predicted by changes in angulation of the fractured humeral head and can be used for individual patients to predict functional outcome. MATERIALS AND METHODS: Standard anteroposterior (AP) and transscapular (Y) radiographs were used to evaluate 55 patients with minimally displaced proximal humeral fractures during the first week of conservative treatment. Functional outcome was determined by the Constant-Murley and Disabilities of Arm, Shoulder and Hand (DASH) scores. The relationship between the variables and the radiographic evaluation was assessed by the Pearson correlation coefficient. Receiver operator curve (ROC) analysis and logistic regression analysis defined the optimal value for abnormalities on radiographic evaluation as an outcome predictor. RESULTS: Mean (SD) angulations at time of the fracture were 53 degrees (19 degrees ) on AP view and 59 degrees (21 degrees ) on Y-view. After 1 week, these angulations were 47 degrees (20 degrees ) and 62 degrees (21 degrees ), respectively. Significant correlations between Constant-Murley (R(2)=0.43, P=.007) and DASH (R(2)=0.43, P=.04) outcome scores and the angulation of the humeral head fragment on the Y view, and not with AP angulation were found. The optimum predictive angulation at the Y view at time of fracture was 55 degrees or less for predicting adverse functional outcome with an area under the ROC curve of 0.78 (95% confidence interval [CI], 0.64-0.93; P=.006). Regression analysis showed that angulations on the initial Y view and after 1 week were the most important predictors of the functional outcome at a median of 2.2 years of follow-up. CONCLUSION: This study indicated that radiographic evaluation in patients with minimally displaced proximal humeral fractures is helpful in prediction functional outcome during conservative treatment.