Retention of intra-articular loose bodies following reduction of traumatic dislocation of the hip frequently leads to unsatisfactory resuls; therefore, their presence was often considered to be an indication for arthrotomy. Here we report one case of the retention of the infra-articular loose fragments following reduction of traumatic hip dislocation. We used arthroscopy instead of open arthrotomy to retrieve them to retrieve them successfully. The postoperative course was smooth and the patient did well. After 13 months’ follow-up, his hip functions was fully restored and no discomfort was complained of.