We report on a 57-year-old woman with three episodes of ischemic strokes and hereditary hemorrhagic telangiectasia (HHT). Tests for inherited and acquired thrombophilia showed elevated anticardiolipin immunoglobulin (Ig)M antibodies (on three separate occasions), anti-prothrombin IgG antibodies, and the heterozygous form of factor V Leiden. This is the first case of HHT, a primary antiphospholipid syndrome, combined with factor V Leiden. No detectable arteriovenous malformation was found and ischemic episodes, documented by computer tomography, were related to the presence of antiphospholipid antibodies and possibly the carriership of factor V Leiden mutation. Since aspirin provoked severe nasal hemorrhages, treatment with ticlopidine was initiated after the third stroke. Over an 18-month follow-up, ischemic episodes were absent and we regarded oral anticoagulation as unjustifiable.