Posterior shoulder dislocation is a lesion of the humeral head prolapse towards the posterior pelvis of the shoulder caused by direct backward force in front of the shoulder joint or by extreme adduction and internal rotation of the shoulder joint during trauma. It is rarer than the anterior dislocation of the shoulder and has a higher rate of missed diagnosis and misdiagnosis. Clinically, there is often a significant defect in the medial side of the humeral head, namely reverse Hill-Sacks injury. We treated a 3-week case of posterior dislocation of the shoulder with inverse Hill-Sacks injury, and summarized clinical data and literature review, in order to provide new ideas for dialectical diagnosis and treatment of PSD.