Nontraumatic shoulder instability is infrequent in children. We examined prospectively with high-field magnetic resonance imaging (MRI) 11 patients with this disorder, including 2 with Holt-Oram syndrome and 11 healthy control subjects. The MR findings in the glenohumeral joint in normally growing children are presented. Two patients with shoulder instability were considered as normal, one presented with type 2 (Zlatkin) labral lesions, three, type 3 and one, type 4 lesions. Close attention to the normal imaging patterns of the maturing glenohumeral joint is required to avoid pitfalls in the interpretation of the images.