There is no one large study on pediatric shoulder instability. The purposes of this study were to characterize patients with shoulder subluxation or dislocation, the treatments provided, outcomes, and the predictors of good outcomes. Seventy shoulders in 66 patients were retrospectively reviewed, all with follow-up >2 years. The authors defined characteristics, treatment, outcomes, and associations between patient and treatment variables and outcome measures. Instability was associated with boys, adolescents, and trauma. Forty-two shoulders received physical therapy, and 28 required surgery. At follow-up, 54 of 70 described their shoulders as "better" or "much better," and 90% were performing at the same or higher levels of sports and work. Surgically treated patients were less likely to have recurrent instability or to report limitations. The current study is a large study of pediatric shoulder instability. Surgery improved stability, but overall, stability improved over time, with few patients having limitations at moderate- to long-term follow-up.