Pyoderma gangrenosum is a severe neutrophilic dermatosis that may occur as a complication following any kind of surgery. Although mainly reported secondary to breast surgery, it may also arise in orthopedic surgery. Misdiagnosis risks serious sequelae, due to inappropriate or delayed treatment. Unlike the infections, which it mimics, it is to be managed by corticosteroids, and debridement is absolutely contraindicated, as it will cause dermatologic lesions in the traumatized areas, worsening and accelerating the pathologic process. As anatomopathology tends to shed little light, it is essential to bear the diagnosis in mind in case of any early superficial pustular lesion showing rapid extension despite correctly administered antibiotherapy. We report a case of pyoderma gangrenosum secondary to hip replacement surgery, and detail diagnostic factors and means of treatment.