We evaluated the total red cell Ca2+ content and the macro- and microrheological determinants in a group of subjects with vascular atherosclerotic disease (VAD). From the results obtained it is evident that, compared to controls, the VAD group presents an alteration of the macro- and microrheological parameters. No difference is evident for the red cell Ca2+ content in normals and in VAD subjects. No relationship is present between total red cell Ca2+ content, VBC (volume blood cells), MEA (mean erythrocyte aggregation) and red cell membrane fluidity expressed as Iex/Im ratio. In contrast to the latter, are the correlation between the red cell Ca2+ content and the degree of polarization obtained with fatty acid probes.