Protein S, a vitamin K-dependent plasma protein, is a cofactor for protein C, an essential component of the regulatory system of coagulation. We describe the anaesthetic management of a parturient with protein S deficiency and an indwelling lumboperitoneal shunt, which was placed following transverse and sagittal sinus thrombosis. She was treated with aspirin and enoxaparin during pregnancy and underwent caesarean section under general anaesthesia without complication.