Background: Glenoid bone loss can affect the outcome and treatment for posttraumatic recurrent anterior glenohumeral instability. Clinical presentation in the adolescent age group with shoulder instability and glenoid bone loss is largely unknown. On the basis of this information, we believe there will be a high incidence of glenoid bone loss in adolescent patients with recurrent glenohumeral instability. We hypothesize that highimpact injuries, sports injuries, and reductions requiring sedation will be factors associated with glenoid bone loss. Methods: We performed a retrospective cross-sectional cohort study reviewing consecutive adolescent patients (n=114) with recurrent traumatic glenohumeral instability between 2004 and 2012. Chart analysis included demographic, presenting, and radiographic data. Glenoid bone loss was interpreted from plain radiographs, computed tomography (2D and/or 3D), magnetic resonance imaging, and/or arthroscopy. We compared possible risk factors between subjects with and without glenoid bone defects using the w 2 test or 2 sample t tests. Results: Glenoid bone loss was seen in 55 patients (48.2%) with 15 of these patients (27%) having critical bone loss. Forty-five percent of appreciated glenoid bone loss was not visualized on plain radiographs. The average age was 15.1 years (range, 6.5 to 18.1) with male to female ratio 3.7: 1. Male sex, older age, and taller stature were all statistically associated with glenoid bone loss (P=0.02, 0.01, and 0.02, respectively). Primary dislocations that occurred during sports were more likely to have glenoid bone loss (55.9% vs. 78.2%, P=0.01). The presence of an apprehension sign on physical examination was positively correlated with bone loss (P=0.008). Conclusions: The presence of glenoid bone loss in primary traumatic glenohumeral instability in the adolescent population is high, however, not as high as previously reported. Factors associated with glenoid bone loss include male sex, older age, taller stature, sports injuries, and the presence of apprehension on physical examination. Level of Evidence: This study establishes patients who may be at high risk for glenoid bone loss based on mechanism of injury and physical examination findings. This prognostic study is a level II retrospective study.