Motivated by the design and manufacturing of customized cushions for debilitated patients, we propose the idea of performance-tailored mesostructures which can change or adapt their design performance based on given requirements. Our goal is to develop a CAD tool with the capability of specifying heterogeneous material properties in a product component such that a designer can design the component with better performance. Based on the object oriented programming paradigm, we first define a performance-tailored mesostructure and its properties. We then demonstrate an approach of building discipline-specific performance models for such mesostructures. For a product component design, we present a performancetailored mesostructure design method based on a hierarchical design framework. A CAD system based on the proposed design framework is being developed which can generate CAD models with performance-tailored mesostructures. The generated CAD models can then be fabricated by a layer-based rapid manufacturing system. Several experimental examples are given to demonstrate the capability of our method.