Dislocations of the shoulder are the most common joint dislocations seen in the emergency department, and complications of shoulder dislocations are more frequent than is generally believed. It is vital that emergency physicians have current knowledge of complications associated with shoulder dislocations because of their important role in recognition and prevention. Delayed recognition of complications can have an impact on the long-term outcome of patients. Prompt recognition and follow-up are essential. Most references address reduction methods rather than recognition of specific complications. Emergency physicians have few opportunities to update their knowledge of complications of shoulder dislocations. This article briefly reviews mechanisms of shoulder dislocation and discusses complications in light of the mechanisms of injury.