Erythrocyte aggregation has been consistently associated with insulin resistance, central obesity and hypertension in the literature. Oxidative stress and chronic inflammation are almost always present in metabolic syndrome (MetS). Prooxidants and adipocytokines generated in MetS alter erythrocyte morphology, decrease erythrocyte deformability and increase whole blood viscosity (WBV). Increased WBV has been attributed to erythrocyte aggregation which in turn is greatly influenced by other rheological parameters, including its membrane surface charge and plasma fibrinogen concentration. The interplay of hemorheological factors, oxidative stress and inflammation has a detrimental effect in MetS due to the gross disturbance in microcirculation. The hemodynamic aspect of MetS needs further research and exploration.