The Rio Iguaçu originates near Curitiba in the Serra do Mar at approximately 1,200 meters elevation and flows roughly 1,320 kilometers westward through Paraná before joining the Paraná River at Foz do Iguaçu. Its drainage basin covers around 62,000 km². Average discharge near the mouth runs approximately 1,836 m³/s, though flows at the Iguazu Falls gauge range from a recorded minimum of 200 m³/s to a maximum of 12,799 m³/s, reflecting the river's significant variability.

Organized paddling activity on the Rio Iguaçu is concentrated near Foz do Iguaçu, within the Iguaçu National Park. Access to the water is typically reached via the Trilha do Índio, a roughly 1.4-kilometer hiking trail through Atlantic rainforest that leads to the riverbank. From there, guided kayak and paddleboard tours operate within an area of approximately 2 kilometers along the river. The surrounding vegetation is dense rainforest, and wildlife commonly observed along this stretch includes parrots, harpy eagles, and armadillos. Waterfalls visible from the water include Cachoeira da Toca and the Juruvá waterfall. Guided tours in this area typically run three to five hours and combine paddling with hiking.

Separately, the Macuco Safari operates motorized boat tours on the Rio Iguaçu within the park, launching from a platform on the right bank approximately 4,000 meters downstream of the Falls and traveling toward the falls themselves.

Independent paddlers should be aware that access to the river in the national park area is managed through organized tour operators, and guides speaking English, Spanish, and Portuguese are available. Given the extreme flow variability documented at the Falls gauge, paddlers planning trips should account for seasonal water level changes when selecting routes or timing visits.