Jesuit missionaries recognized it as distinct from Waikuri (Guaycura) immediately to the north.

It was spoken in the mountainous area around the mission of San José del Cabo, on the southeastern coast from Santiago to La Paz, and on the islands off the east coast as far north as Isla San José.

However, with the benefit of several decades of subsequent research, Laylander (1997) and Zamponi (2004) conclude that the languages were unrelated.

The Pericú may have shared with the Waikuri distinctive physical characteristics such as small bodies and dolichocephalic crania (long-headedness).

Variations of the name include Waicuri, Guaicuri, Waicura, Guaycura, Guaicura, Waicuro, Guaicuro, Guaycuro, Vaicuro, Guaicuru, Guaycuru, Waikur.