The effects of several different compatibilizing agents with reactive functional groups (acid and/or anhydride) on the morphology of blends of styrene-acrylonitrile copolymers (SAN) in polyamide (PA) matrices were investigated using transmission electron microscopy. The primary focus was on the use of a series of imidized acrylic polymers and how their functionality for reaction with nylon-6 and their miscibility with SAN copolymers affected the morphology of nylon-6/SAN blends. Glass transition behaviour of binary blends of the imidized acrylic polymers with SAN systems indicated that miscible blends over a restricted range of AN content in the SAN could be obtained by limiting the imide and free-acid contents of the imidized acrylic polymers. In the case of the ternary polyamide blends, the most efficient reduction in the dispersed-phase particle size was obtained via imidized acrylic polymers that are miscible with the SAN phase and can react with the polyimide to a significant degree. For nylon-6/SAN blends compatibilized with polymers containing a high level of anhydride functionality, complex morphologies consisting of at least two distinct populations of dispersed phase were observed. The factors responsible for generation of such complex morphologies were examined using different staining techniques, and it was proposed that a theological effect is the dominant issue. The chemical functionality characteristics of the polyamide matrix were also shown to have an effect on the morphology of nylon/SAN blends compatibilized with imidized acrylic polymers.