Hydroxymethylglutaryl Coenzyme A reductase (HMGCoA-red) inhibitors are cholesterol lowering drugs which display pleiotropic effects on several cell types including endothelial cells (EC). Patients with antiphospholipid syndrome (APS) are characterized by the persistent presence of antiphospholipid antibodies (aPL) and by a high incidence of recurrent thrombotic events. aPL have been demonstrated to bind and activate cultured human EC thus contributing to a prothrombotic state. We evaluated the ability of HMGCoA inhibitors to affect the EC activation induced in vitro by aPL and in particular by antibodies reacting with the PL-binding protein β2 glycoprotein I (β2GPI). Both human monoclonal IgM and polyclonal IgG anti-β2GPI antibodies were used. EC activation was evaluated as adhesion molecule (ADM) expression and cytokine production.