It forms from the confluence of the Ecuadorian rivers Conambo and Pintoyacu at the Peruvian border.

Its mouth is 42 mi (68 km) west of the junction of the Ucayali River with the Marañón.

Continuing west from the Tigre along the Marañón River are the Parinari, Chambira, and Nucuray, all short lowland streams, resembling the Nanay in character.

Tigre is Spanish for "tiger", the vernacular name in the region for the Jaguar .

This article related to a river in Peru is a stub.