Protein C and S are vitamin K-dependent natural anticoagulants. They play a major role in hemostasis by degrading the activated factor V and factor VIII. Deficiencies of protein C and protein S are associated with increased risk of thrombotic events. The combined occurrence of protein C and S deficiency has been rarely reported. We report a 6-year-old boy with Budd-Chiari syndrome due to combined protein C and protein S deficiency. He was managed with low molecular weight heparin and discharged on long-term warfarin therapy.