Mechanical modeling and dynamic mechanical analysis were associated to investigate the viscoelastic properties of an alkyd acrylic hybrid system in connection with its morphology, which was characterized by transmission electron microscopy. Theoretical predictions based on the interlayer model used in direct mode were successfully combined with the experimental viscoelastic data to lead to relevant additional information about the complex particulate morphology of the hybrid system. Thus, using direct mechanical modeling, it was concluded that the experimental response of the alkyd acrylic hybrid system to a sinusoidal mechanical stress corresponds to the mechanical response of a sample whose morphology involves a acrylic-rich interphase between continuous and dispersed alkyd-rich domains. For the very first time, the interlayer model was then used in reverse mode in order to separate the actual viscoelastic properties of such a acrylic-rich interphase from those experimentally obtained for the alkyd acrylic hybrid system. The differences in these extracted viscoelastic properties, when compared to those of the pure latex film, were presented as reflecting the changes in the molecular mobility of the macromolecules resulting from the mutual influence of the phases in the multiphase hybrid material.