ECO was founded in 1971 as CoEnCo to meet the needs of the conservation community. We became ECO in 1976. We are a non-profit network of 70 organisations with a concern for conservation and the environment.

Our membership includes large international groups such as Greenpeace and Friends of the Earth, national groups including Federated Mountain Clubs of New Zealand and the National Council of Women, as well as small local groups such as Kapiti Environmental Action and Save the Otago Peninsula, and issue oriented groups like the Biodynamic Farming and Gardening Society and the Yellow-eyed Penguin Trust.

ECO has been centrally involved in campaigns to protect native forests, lakes and rivers, the reform of the Mining Act and defeat of the National Development Act, and in supporting the Resource Management Act and the establishment of the Department of Conservation and Ministry of the Environment. ECO continues to be at the forefront of environmental campaigns on fisheries, transport and environmental management.

ECO organises an annual conference on environmental issues at the end of June.  The 2007 Conference was held in Nelson and the 2008 Conference will be in Wellington.

ECO`s work is carried out largely by volunteers, supported by a small office and resource centre in Wellington. There are around 500 "Friends of ECO," individual subscribers who support our work.

As well as working within New Zealand ECO maintains links with international networks, including the World Conservation Union [IUCN], Environment Liaison Centre International [ELCI], Antarctic and Southern Ocean Coalition [ASOC], and Climate Action Network [CAN].