Primary antiphospholipid syndrome (PAPS) is a recently recognized clinical entity encompassing the combination of thromboembolic phenomena, thrombocytopenia and recurrent abortions in the presence of antiphospholipid antibodies. We present a patient with PAPS accompanied by renal involvement, manifested as membranous nephropathy, as proven by a renal biopsy. To investigate further the possible association between PAPS and the renal lesions we attempted to induce similar renal manifestations by transferring peripheral blood lymphocytes (PBL) from this patient to severe combined immunodeficiency (SCID) mice. The mice transfused with PBL from the affected patient exemplified antiphospholipid antibodies (aPL) following which a renal lesion consistent with the human membranous nephropathy lesion was precipitated. This study substantiates the role of aPL as possible inducers of renal damage.