We examined the management options used for epistaxis of varying severity in patients with hereditary hemorrhagic telangiectasia (HHT) to develop a treatment algorithm. Fifty patients with HHT were studied from 1991 to 1997 to consider various treatment options and their relative efficacy. There were 28 females and 22 men; their ages ranged from 15 to 85. Follow-up ranged from 6 months to 6 years. A wide variety of treatments had been used (including various forms of cautery, septal surgery, topical and systemic hormones, antifibrinolytic therapy, arterial ligation, laser therapy, and closure of the nostrils). Treatments used during the follow-up period were argon laser therapy (40), systemic estrogen or progesterone (17), septodermoplasty (12), or closure of the nostrils (14). Patients were divided into those with mild to moderate disease (requiring one or no blood transfusions during the course of their illness) and those with severe disease (requiring more than one blood transfusion). Using this broad categorization, those with mild to moderate disease did well with sequential argon laser therapy with or without the adjunct of septodermoplasty or hormone therapy. Those with severe disease did not find argon laser therapy beneficial but found their epistaxis completely stopped with closure of the nasal cavities. Based on these findings, a simple treatment algorithm defines the optimum treatment options for epistaxis in this difficult-to-treat group of patients.