The growing needs for reducing weight in high performance applications such as in automotive, transport and aeronautic industries is leading to wider use of foams in lightweight structures, such as sandwich structures, and in applications where low thermal, acoustic and electric conductivity are required. The service temperature of these conventional materials are not much different from the room temperature but stringent requirements in high performance applications is resistance of materials to high service temperatures and challenging environments. Recently composite foams based on thermoplastic polymer matrix (PEN) were developed by CNR-IMCB with the aim to increase specific structural properties, such as impact resistance, through the introduction of micrometric voids between reinforcing fabrics and inside fiber bundles. This multi-scale approach, mined from lightweight composite structures widely available in Nature such as in wood or bone, was exploited to allow the spreading of the load over larger regions in the lightweight composite structure with respect to conventional solid polymer composites. In order to extend the structural performances over a wider temperature range and to reach higher continuous service temperatures, a co-continuous binary blend of a semicrystalline (PEN) and an amorphous (PES) high performance polymers has been designed to be used as matrix for the production of high performance foamed composites. As a further advancement of the concept, expanded graphite was used to increase the mechanical performance of the matrix and to extend at the sub-micrometric scale the cellular morphology of the foamed blend. In this work, processing parameters for the production of high performance blends and foams have been related to the physical-chemical and structural properties of solid matrix and foams, in order to maximize the specific performances and improve the foams morphology.