Blends of diglycidyl ether of bisphenol-A epoxy resin and adipic acid, ethylene glycol, diethylene glycol polyester copolymer have been studied regarding viscosity behavior. Both the rheological measurements carried out on the molten mixtures over a large interval of shear rates and the intrinsic viscosity of the blend solutions pointed to an immiscibility at temperatures ranging from 30 degrees to 90 degrees C. The theological parameters evaluated on the flow of the mixtures against temperature and the shear rate led to the conclusion that the tested blends have a non-Newtonian theological behavior of the pseudoplastic type.