The diagnosis of acute circulatory failure in the postoperative course of hip replacement must concentrate on frequent complications, but rare complications requiring specific treatment must also be diagnosed. We report on the occurrence of a case of acute adrenal insufficiency subsequent to enoxaparin-induced type II thrombocytopenia. A delay was necessary to establish a correct diagnosis for two reasons: (1) an unusual clinical presentation and (2) an underevaluation of the medical risk during the preoperative visit. The evolution was nevertheless favorable after prescription of steroids that had to be prescribed chronically.