Abstract The prevalence of inherited bleeding disorders (BDs) is low in the general population (10–20 per 100,000 individuals), particularly hemophilia B cases, which may remain undiagnosed for a very long time until exposed to some surgical procedure. The dental professional must be aware of the possibility that patients with no previous history of abnormal bleeding may manifest their first bleeding episode in the dental office. Particularly as periodontists, we often encounter patients with bleeding gums and severe bleeding complications may precipitate while performing routine periodontal procedures. Hence, we must have a thorough knowledge of BDs and their management in challenging hemorrhagic situations. Management of such patients necessitates a multidisciplinary approach by involving the patient’s hematologist and advanced laboratory facilities. The present case report is an attempt to discuss the diagnosis and management of a bleeding episode that occurred post periodontal flap surgery in an undiagnosed hemophilia B patient.