The origins of OIDHACO go back to 1993, thanks to a proposal from HEKs Switzerland to join the efforts of European organisations and Protestant churches working on Colombia and exchange worries and strategies. During the next two years it extended to other European church and human rights organisations. In February 1995, the European Parliament held the European Conference on Human Rights in Colombia, and, given its success, the participating organisations from Colombia and Europe decided to establish permanent mechanisms to follow up and strengthen lobbying for Colombia in Europe. Later, the London Agreement was created setting the base for the establishment of OIDHACO, uniting more European organisations to strengthen work in favour of human rights in Colombia.
In 1995, the Association of the International Office of Human Rights Action on Colombia (OIDHACO) and the Colombia Europe Coordination were created. As time went by, more organisations from different European countries joined as effective members or as observers and three more platforms from Colombia also joined. OIDHACO worked as a network without legal person for 14 years and in 2009 was constituted as a non-for profit association (asbl) with headquarters in Belgium. It currently includes 30 members in 9 countries.