Professor Denardo was associated with ICTP since the Centre's inception. He served as head of the Office of External Activities for 10 years as well as a consultant of the Office after his retirement up until his last day.  From July 2002 to October 2003, he was appointed Acting Administrative Director. He was instrumental in  establishing and running all ICTP activities on optics and lasers, including the Laboratory and the ICO/ICTP Award.

Denardo was one of the Centre's loyal, cheerful and active friends. With creativity and dedication, he helped to establish and run other programmes—among them, the Sandwich Training Educational Programme (STEP)  in collaboration with the IAEA.

In 2005 Denardo received the SPIE Educator Award for his efforts in promoting optics in developing countries.  He was especially devoted to enhancing optics research and training in Africa.