Background: Hip resurfacing arthroplasty has been presented as an alternative for management of symptomatic hip osteoarthritis in young patients with developmental dysplasia of the hip. However, complications such as femoral neck fractures may occur, especially in patient with certain risk factors. Clinical case: We present the case of a 44 year-old women with developmental dysplasia of the left hip treated with hip resurfacing. Four years after surgery, the patient consulted at our trauma center with a femoral neck fracture and radiologic signs of mal positioning of the acetabular component. A type-B postnecrotic periprosthetic fracture associated to metallosis due to mal positioning of the acetabular cup was evidenced. We decided to perform a conversion to total hip arthroplasty. Conclusions: The indication of hip resurfacing in patients with DDH has risks of major complications in the short term, such as periprosthetic femoral neck fractures and metallosis. The conversion to THA is not an easy surgical procedure, requiring a careful preoperative plan and an experienced surgical team. © J ORTHOP TRAUMA SURG REL RES.