The first reports about the Rikbaktsa date to the decade ending in 1940 when rubber tappers first penetrated the equatorial forests of the Sangue, Arinos, and Juruena rivers. The absence of previous historical references and archaeological studies makes it impossible to determine the antiquity of the occupation of Rikbaktsa territory. Extensive and detailed knowledge about the fauna, flora, and geography of the area and its surroundings exists, however, which leads to the conclusion that human occupation has been rather lengthy. The Ribaktksa, known for their warlike ethos, had hostile relations with all nearby tribal groups: the Cinta Larga and Suruí to the west, in the Rio Aripuanã Basin; the Kayabí to the east and the Tapanhuma to the southeast on the Rio Arinos; the Iranshe, Paresí, and Nambicuara to the south, on the Rio Papagaio and the headwaters of the Juruena; the Mundurucu and Apiaká to the north at the lower course of the Rio Tapajós. The Rikbaktsa fought with the rubber tappers until 1962, when they were pacified by Jesuits who were financed by the owners of rubber-tree plantations. The high mortality rate after contact destroyed Rikbaktsa society. A large number of the children were taken from the tribe and brought almost 300 kilometers away, to the Utiariti Jesuit school on the Rio Papagaio, where they were educated together with children from other tribal groups. The remaining adults were gradually transferred from their original villages to larger and more centralized ones, also under the control of the Jesuits.
In 1968 a small part of Rikbaktsa territory was marked off, the children were returned to the tribe, and missionary activities were centralized on the reservation. From 1970 on, there were several attempts to invade Rikbaktsa territory owing to increasing population density in the general area. This was accentuated during the 1980s by heavy migration, caused by the Programa Polonoroeste, the main activity of which was paving the Cuiabá-Pôrto Velho highway (financed in part by the World Bank). After armed conflict and judicial court action, the Rikbaktsa were able to achieve the demarcation of another area of their territory in 1986. They have had serious health problems and have been devastated by malaria and tuberculosis. Their relations with neighboring tribal groups are those of political alliance in defense of their territories and indigenous rights. Missionary influence has diminished considerably, and the Rikbaktsa will not permit officials of the Fundação Nacional do Indio (National Indian Foundation, FUNAI) to stay in their territory. The Rikbaktsa have bilingual schools staffed by native teachers and try to gain access to Western knowledge as a way of protecting their autonomy.