Acromioclavicular joint (ACJ) injuries represent a common injury to the shoulder girdle. In the management algorithm of acute ACJ injuries complete radiological evaluation represents the key to a successful therapy. According to the classification of Rockwood the presence of a horizontal component in addition to vertical instability has to be detected. Using axillary functional views or Alexander views dynamic horizontal ACJ instability can be diagnosed in a simple, efficient and cost-effective manner reducing the number of mis-/underdiagnosed ACJ injuries. MRI should not be the imaging modality of first choice. The treatment of ACJ dislocations must consider two aspects. In addition to the correct type of injury therapy strategies should be adapted to patient's demands and compliance. Low grade AC injuries types I and II are treated non-operatively in terms of "skilful-neglect". High-grade injuries types IV-VI should be treated operatively within a time frame of 2-3 weeks after injury. A certain debate is still ongoing regarding type III injuries. Out from the literature, non-operative treatment of type III injuries results to provide at least equal functional outcomes as compared to surgical treatment associated with less complications and earlier return to professional and sports activities. If surgical treatment is indicated, open surgical procedures using pins, PDS-slings or hook plates are still widely used concurring with recently raising minimally invasive, arthroscopic techniques using new implants designed to remain in situ. Combined coracoclavicular and acromioclavicular repair are gaining in importance to restore horizontal as well as vertical ACJ stability.