The linear viscoelastic properties of molten polyethylene terephthalate glycol/polyester-ethylene vinylacetate (PETG/EVA) immiscible blends were measured as a function of frequency for different compositions and temperatures. The morphology of the blends was determined by scanning electron microscopy and the rheological behaviour of the blends is described by the Palierne emulsion model. The behaviour is typical of homogeneous molten polymers except for the appearance of a shoulder in the storage modulus data at low frequencies. This corresponds to an increase in elasticity in the terminal zone and longer relaxation time compared to the matrix. The model describes correctly the experimental data, and the model predictions are used to determine the interfacial tension between PETG and EVA. The interfacial tension is shown to vary between 4.5 mN m(-1) and 7 mN m(-1), depending on composition and temperature. These values are in the range of interfacial tension values determined for other similar polymer systems. No comparison with literature data was possible and an attempt to use the breaking thread method to verify the interfacial tension value for this system was not successful.