The authors report two cases of torsion of Riedel's lobe. The first case resembled acute cholecystitis. Resection was followed by a cure. The second case presented in the form of a complicated abdomino-pelvic tumor. Its removal did not prevent a fatal issue due to fibrinolysis probably related to advanced ischemic infarction of Riedel's lobe of the liver. It seems that these complications are exceptional.