The costo-clavicular ligament is always ruptured in dislocation at the sterno-clavicular joint. Anterior, superior or posterior displacement of the medial end of the clavicle may occur. Acute dislocation usually responds to conservative treatment and operation is seldom required. Chronic, or recurrent, dislocation may cause pain and disability on strenuous activity and necessitate surgical treatment. The operation of tenodesis of the subclavius tendon with capsulorrhaphy described by Burrows (1951) has been adopted. The intraarticular meniscus is often damaged and displaced, and may block reduction; its removal is then necessary. In addition, a threaded Steinmann pin transfixing the joint has been found useful to maintain the stability of reduction. The operation has been performed on five patients, four of whom had excellent results. The fifth patient disrupted the repair in a drinking bout shortly after the operation.