Abstract: A process is provided for producing high temperature composite components from a thermosetting polyimide resin system, and more particularly to an in-mold technique for impregnating a reinforcement fiber preform with the polyimide resin system, and thereafter imidizing the polyimide resin system in such a way that exposure to the uncured (nonimidized) polyimide resin system is minimized. The process entails an injection technique that ensures complete impregnation and wetting of the reinforcing fabric, and complete removal of the condensation byproducts formed during imidization. The imidized component is then cured by heating the component to a temperature sufficient to remelt the polyimide resin system, and then applying pressure and additional heat to cause the polyimide resin system to cross-link to produce the desired composite component. The process results in a fiber-reinforced polyimide matrix component characterized by a void content of less than about three percent.