The effect of nanoplatelets on the rheological behavior of epoxy monomers with variations in nanoplatelet exfoliation level and aspect ratio was investigated. The results show that the presence of exfoliated nanoplatelets in epoxy can significantly influence viscosity and lead to shear‐thinning phenomena, especially when the aspect ratio of the nanoplatelets is high. By employing the Krieger‐Dougherty model, the effectiveness of nanoplatelets in altering epoxy rheological behavior was quantitatively described and compared with experimental findings. Possible physical reasons for the observed rheological behaviors are discussed. The implication of the present study for polymer nanocomposites processing is also addressed.