The acromioclavicular joint is a small, diarthrodial joint that can cause significant pain. A thorough patient history, careful physical examination, and the judicious use of selective injections are critically important to making an accurate diagnosis. Many radiographic findings are unreliable in determining the reasons for a symptomatic acromioclavicular joint. Recent controversy surrounding this joint has centered on the clinical question: should the acromioclavicular joint be left alone, débrided, or resected? A review of the anatomy, pathophysiology, biomechanics, diagnostic criteria, and treatment options for patients with disorders of the acromioclavicular joint can provide information to answer this question.