Established in December 1989 to conduct on-site verification of termination of aid to irregular forces and insurrectionist movements, and the non-use of the territory of one State for attacks on other States in the countries of Costa Rica, El Salvador, Guatemala, Honduras and Nicaragua.The Mission terminated in January 1992.
The medal ribbon contains five narrow green stripes to represent the five countries involved. These five green stripes are separated by four equal white stripes. The central group is flanked by two equal bands of sea blue to represent the Pacific Ocean and the Caribbean Sea, flanked in turn by two broad bands of UN blue to represent the United Nations presence in the area. Ninety days of service in the Mission are required to qualify for the medal.
The countries of Argentina, Brazil, Canada, Colombia, Ecuador, India, Ireland, Spain, Sweden and Venezuela provided observers and troops to ONUCA. Venezuela provided a 700 man infantry battalion to supervise the demobilization, disarmament and resettlement of the Contra factions in Nicaragua, from May to July 1990.