An 11-year-old male with hemophilia A and a known high-titer Factor VIII inhibitor was admitted with retroperitoneal hemorrhage. The patient was receiving infusions of recombinant activated Factor VII (rFVIIa) for a recent elbow hemorrhage when retroperitoneal bleeding commenced. Despite increased dosing of rFVIIa and a dose of activated prothrombin complex concentrate (aPCC), he continued to hemorrhage and required several blood transfusions. Factor XIII was administered 1 hour after rFVIIa and the patient demonstrated cessation of bleeding and normalization of clot strength. Factor XIII may act as an adjuvant in effective clot stabilization in patients with hemophilia and inhibitory antibodies.