Patients with pulmonary arteriovenous fistulas (PAVFs) are at risk for the development of brain abscesses. The history of a 26-year-old man with PAVF, which has remained unrecognized for many years, is reported. Within four years, the patient presented life threatening cerebral abscesses twice at different sites. Treatment consisted of parenteral antibiotics. Finally, the pulmonary arteriovenous fistula has been treated by embolization. This case emphasizes the importance of early diagnosis and treatment of PAVF in preventing central nervous system infections. (C) 1998 Lippincott Williams & Wilkins.