We report a 32-yr-old woman who suffered a stroke as a consequence of arteritis of both internal carotid arteries confirmed by selective carotid arteriography. Laryngeal inflammation and kidney biopsy proven focal crescentic glomerulonephritis were also present in this patient. Anti-neutrophil cytoplasmic autoantibodies with specificity for proteinase 3 were detected in high titre during the active phase of the disease. This overlap syndrome with features indicating both Takayasu's arteritis and Wegener's granulomatosis suggests a common pathogenesis for these diseases.