Both Hansen solubility parameter and Flory-Huggins interaction parameter of two EVA [Poly(ethylene-co-vinyl acetate)] copolymers with different vinyl acetate content have been obtained by means of intrinsic viscosity measurements. To calculate this last parameter it was also necessary to determine the theta solvent at different temperatures of the two EVA copolymers with turbidimetric measurements. The results indicate that the vinyl acetate content is a variable which influences the composition of the theta solvent and Flory-Huggins parameter (the higher the vinyl acetate content, the lower the Flory-Huggins parameter), although its influence over the Hansen solubility parameter is almost negligible.