We present the case of a professional horse jockey with chronic, bilateral, posterior sternoclavicular dislocations. Traumatic dislocation of the sternoclavicular is a relatively rare but potentially devastating injury. Posterior sternoclavicular dislocations occur less frequently than anterior dislocations and require careful and complete evaluation because of the potential for serious complications including respiratory distress, brachial plexus injury, and vascular injury. Our patient was treated with excision of the medial end of the clavicle on her symptomatic side.