Coagulation factor VII plays a crucial role in the extrinsic pathway of the coagulation cascade. Deficiency of coagulation factors, including factor VII, is a rare but recognized cause of abnormal uterine bleeding (AUB) in women. This case report presents an 11-year-old previously healthy girl who arrived at the emergency department with 18 days of heavy menstrual bleeding and hemodynamic instability due to severe anemia. Laboratory evaluation revealed prolonged prothrombin time (PT/INR) with a normal partial thromboplastin time (PTT). A factor VII activity assay confirmed a severely decreased serum factor VII level. Bleeding was successfully managed with recombinant human factor VII. Further family screening showed reduced factor VII activity in the patient's mother and three siblings, while the father's levels were normal, suggesting a possible dominant inheritance pattern. However, genetic testing is required to confirm this hypothesis.