The risks of venous thrombosis and fetal loss are increased in patients with protein C deficiency. We describe a patient with a history of thrombosis and recurrent fetal loss who was found to have type 1 protein C deficiency. In view of her history and intolerance of heparin preparations, she was treated with protein C concentrate during the first and third trimesters of her seventh pregnancy. The patient suffered no thromboembolic event during this pregnancy and gave birth to a healthy infant. The implications of the success of this therapeutic strategy are discussed.