It runs 500 kilometres (310 mi) from the Chapada Diamantina highlands of central Bahia to its mouth at the Baía de Todos os Santos.

In the colonial period it was variously spelled as Paraguaçu, Paraoçu, Paraossu, Peroguaçu, Perasu, Peoassu, or Peruassu.

The Paraguaçu River originates in the Chapada Diamantina highlands of central Bahia following the chain of mountains called Sincura and flows east 500 kilometres (310 mi) to empty into the Baía de Todos os Santos.

[2] The lower reaches of the Paraguaçu cross the Recôncavo, a fertile region that supported sugar cane and tobacco plantation.

The lower reaches of the river is rich in convents and churches of the colonial period, notably in São Félix, Cachoeira, and Maragojipe.

[4] Numerous heritage sites are located along the river, including the historic centers of Jaguaripe, Cachoeira, and São Felix.