DEO was created as a nodal agency in 1981 as part of the Department of Defence Production, Ministry of Defence to promote and export potential of Defence Public Sector Undertakings, DRDO and the Ordnance Factory Board. Over the years, it has immensely contributed towards export promotion activities on behalf of Ministry of Defence. It is the nodal and co-ordination agency for the conduct of two major expositions in India, viz; Aero India and Defexpo India, which have seen exponential growth over the years. DEO also co-ordinates the participation of Indian Defence industries in exhibitions abroad.