Hereditary hemorrhagic telangiectasia (Rendu-Osler-Weber disease) is an inherited abnormality of the vasculature characterized by abnormal subepidermal vessels. Frequent, sometimes severe, epistaxis often requiring blood transfusions is present in most patients. Septal dermatoplasty and estrogen have proved to be the most successful therapies. However, the frequency of failure in treatment has stimulated a search for an alternative therapy. The Nd-YAG laser was used at low-power settings (20-25 W) to treat 6 patients with hereditary hemorrhagic telangiectasia, all of whom had been treated previously using other modalities. Laser photocoagulation diminished the frequency and severity of hemorrhage in 5 of 6 patients without complications (6 to 9 month follow-up period). The Nd-YAG laser may be used repeatedly when new accessible lesions arise, and it appears to be a useful therapeutic option for this disease that is difficult to treat.