The serum vascular adhesion molecule ICAM-1 that is involved in atherogenesis was determined in fertile, postmenopausal and at term pregnant women. The aim of the study was to ascertain if the antiatherogenic estrogens action may involve this adhesion molecule. The serum ICAM-1 concentrations resulted similar in the three groups studied: 331 +/- 35 ng/ml, 333 +/- 28 ng/ml and 302 +/- 53 ng/ml in fertile, postmenopausal and pregnant subjects respectively, despite the very different estrogen plasma levels. These data, the first on the ICAM-1 serum levels in women with different natural hormonal milieu, demonstrate that estrogens antiatherogenic action is not involving ICAM-1.