The HELLP syndrome (hemolysis, elevated liver enzymes and low platelets) is a thrombotic microangiopathic vasculopathy that presents in pregnancy. HELLP syndrome usually resolves with delivery of the fetus without sequelae and is often managed successfully with conservative care. To our knowledge, there has been no prior report of an association between HELLP syndrome and elevated titers of antiphospholipid antibodies (aPL). We describe 2 patients who each presented with HELLP syndrome that was refractory despite delivery of the fetus, corticosteroids, and anticoagulation. Both patients had elevated levels of anticardiolipin antibodies. Examination of skin and placental pathology revealed diffuse deposition of fibrin with small vessel thrombi, without evidence of vasculitis. Coincident with plasmapheresis, HELLP resolved in both patients. We conclude that there may be an association between the presence of aPL and a protracted HELLP syndrome in pregnancy; this may be a new manifestation of the antiphospholipid syndrome. Plasmapheresis appears to benefit these patients. Further investigation into this association is warranted.