The word chamacoco means 'person', but currently it’s also used with the meaning of 'indigenous' in opposition to the Paraguayans (Maro).

The Chamacoco are an indigenous people of Chaco Boreal who inhabit the department of Alto Paraguay along the coast of the Paraguay River, as well as small groups who have migrated to other departments. In Brazil, there is a small indigenous group in the state of Mato Grosso do Sul.
According to the results of the 3rd National Population and Housing Census for Indigenous Peoples in 2012, about 1,800 Chamacoco live in Paraguay.

Their language, called Yshyr Ahwoso, belongs to the Zamuco language family, studied and described by the Jesuits in the 18th century. It is considered an endangered language by UNESCO and could disappear in a few generations under the pressure of culturally dominant languages in the region such as Spanish and Guaraní.

The Chamacoco were originally a semi-nomadic ethnic group that practised gathering, hunting and fishing. The Chamacoco population was divided into patrilineal and exogamous clans. The shaman (konsehet) played a central role as he had to fight against evil spirits that brought misfortune and disease. The Chamacoco used birdsong to draw premonitory signs. Religious practices involved a strict distinction between the sexes. For men, there was an initiation ceremony. Upon reaching puberty at 12 or 13 years of age, boys would go out alone into the wild and return when they managed to hunt an animal that they shared with the community, thus becoming adults. They would then be taken to the tobich and educated in the Yshyr culture.

The extended family, consisting of parents, children with their wives and children, lived together. In turn, the houses were grouped by totemic clans. The traditional village or lut was organised in the shape of a crescent, with one of its points facing north and the convex part facing east.
According to current references, the first tobich (sacred place) was established at a point known as Karcha Balut (big shell) on the river, today Puerto 14 de Mayo.

Bruno Barrás, who belongs to the community of Potreritos, follows the ancient Yshyr tradition of polygamy and has three wives. This is how Bruno describes the culture of his people:

"The mythology of Ebytoso has three powers: the water goddess Eshnuwerta takes care of the life of aquatic animals. The goddess of the air, Pauchata, is the sentinel of the sky, space and wind. and the forest god Nemur, of all the plants and animals that dwell in it. The forest is where we learn what we need, Mother Nature, is a university, as the white man says. Nemur taught men how to use the four-legged animals and how to use the flora. And Eshnuwerta taught us how to use fish, without harming them or disturbing the balance, This is wisdom for us. There are predictions from all three gods. Nemur said that if men start destroying the flora, it may bring pestilence or very serious epidemics to the nations, whatever they may be. For this is the life of human men on earth. Rare parasites can come to attack human beings. The same thing Eshnuwerta said: if you don't use aquatic animals well, nature and the source of the flow of rivers will refuse, will rebel and they will have to suffer the consequences of droughts, floods, because fish also breathe air, just like human beings. And Pauchata's prediction is: when humans do not take care of their environment, then the sun can become more and more furious and storms can come with great speed to touch the nations. The air deserves respect because we all need it more than anything else.”

The Yshyr Chamacoco also have another fundamental mythical institution that promotes the balanced use of resources and habitat, the Animal Lord. Each animal has its owner, a balut, or advocate, who facilitates hunting while severely punishing its excessive use.

The Chamacoco are mentioned for the first time in a document that dates back to 1795. The first contact with whites took place from the 1880s onwards. A turning point in the relations between the Chamacoco and western civilisation occurred as the Italian explorer and photographer Guido Boggiani carried out linguistic and anthropological studies on this ethnic group. He also founded Puerto 14 de Mayo and Puerto Esperanza, before being killed by the Chamacoco during an expedition to the Chaco.

In ancient times, the Chamacoco were divided in two warring groups: Chamacoco Ebitoso, and Chamacoco Tomaraho. During the Chaco War (1932-1935), fought between Paraguay and Bolivia, the two groups helped the Paraguayan soldiers in their fight against the Bolivians, but at the end of the war, they lost their territories and had to negotiate their survival with Paraguayan settlers and new landowners.

The Ebitoso later experienced evangelisation by missionaries from the New Tribes, who managed to put an end to ritual celebrations and underwent a strong process of cultural disintegration. The Tomaraho, thanks to their isolation, have preserved their ethnic identity to a greater extent, remaining in the forest and far from the influence of Paraguayans and missionaries. At the cost of near extinction, the Tomáraho managed to preserve a large number of their myths, shamanism and traditional ceremonies. The Yshyr were displaced from their lands and relocated by the National Indigenous Institute of Paraguay (INDI), confining them to small areas along the river in the 1980s.

These groups are now on the verge of disappearance due to poverty resulting from the transformation of their habitat, the degradation of natural resources and the pressure of expanding economic activity.

Young people migrate to the cities of Paraguay and Brazil, abandoning their customs and often denying their origin to avoid discrimination. The Yshyr now survive on a precarious livelihood of growing cassava, sweet potatoes, beans, maize, pumpkin and watermelon. They also hunt, fish and collect honey and carandá palms, and manage to earn a little money from the sale of their handicrafts. Some groups of Yshyr dissidents, known as 'yacareceros', poach alligators: fifteen to twenty men travel by canoe through the swamps of the Negro River, where they hunt for a month, sleeping in their boats, constantly exposed to the weather and dangers, including Brazilian forest guards, most of them ex-convicts, who shoot them on sight.

In 2009, only three ebitoso communities held legal status and their own land; the community of Tomáraho does have legal status but their land has been assigned all the same to companies that hold no right to it, ( DGEEC , 2004) for a total of 25,828 hectares.

"Now our territory is that of the company, we live there, but it is not our land, it no longer belongs to us and has become an enemy place that is killing us. Before, we were brave and strong, but living with the Paraguayans has tamed us".

Their material culture differed from other ethnic groups in the Chaco as they made objects out of feathers and used birdsong as a warning sign since ancient times.