Pulmonary arteriovenous fistula is an unusual but not rare abnormality with more than 450 cases reported in the literature. Studies during the last 30 years have established the effective prevention of morbidity and relief of symptoms by operative excision. During the last 25 years, the Vanderbilt University Affiliated Hospitals have seen 7 patients with pulmonary arteriovenous fistula. This experience prompted a review of the literature. Particular emphasis is placed on current means of diagnosis and therapy.