Primary osteoarthritis of the sternoclavicular joint (SCJ) is relatively common, occurring in 90% of people over age 60, and must be considered in the differential of chest wall pain. Lesions typically appear after age 40 years and are either bilateral or slightly more common in the SCJ of the dominant hand. Diagnosis by plain x-rays is confounded by overlapping structures; therefore SCJ osteoarthritis is most easily diagnosed by classic radiographic findings on computed tomography of the sternoclavicular joint. Treatment consists of rest, physical therapy, non-steroidal anti-inflammatory drugs, or local corticosteroid injection, with surgery for those with intractable pain.