How many countries are generally associated with the Congo rainforest?

The Congo is the Earth's second largest river by volume, draining an area of 3.7 million square kilometers (1.4 million square miles), known as the Congo Basin. Much of the basin is covered by rich tropical rainforests and swamps. Together these ecosystems make up the bulk of Central Africa's rainforest, which at 178 million hectares (2005) is the world's second largest rainforest.

While nine countries (Angola, Cameroon, Central African Republic, Democratic Republic of the Congo, Republic of the Congo, Burundi, Rwanda, Tanzania, Zambia) have part of their territory in the Congo Basin, conventionally six countries with extensive forest cover in the region are generally associated with the Congo rainforest: Cameroon, the Central African Republic, the Republic of Congo, the Democratic Republic of Congo (DRC), Equatorial Guinea and Gabon.

Technically most of Gabon and parts of the Republic of Congo are in the Ogooue River Basin, while a large chunk of Cameroon is in the Sanaga River Basin. Of the six countries, DRC contains the largest area of rainforest, with 107 million hectares, amounting to 60 percent of Central Africa's lowland forest cover.