Self-healing is receiving increasing interest worldwide as a technology to autonomously address the effects of damage in composite materials. This article relates to a self-healing composite exhibiting high levels of healing efficiency under working conditions typical of aeronautic materials. The self-healing material is composed of a thermosetting epoxy matrix in which a catalyst of Ring Opening Metathesis Polymerization (ROMP) and nanocapsules are dispersed. The nanocapsules contain a monomer able to polymerize via ROMP. Dynamic mechanical analysis was used to determine mechanical parameters. The autorepair composite shows a high modulus in a wide temperature range, a glass transition temperature at about 110C and a selfhealing efficiency of about 97%.