The rains flooded streets, the capital city's metro line and peoples' homes, bringing down trees and causing landslides.
Rio's Mayor Eduardo Paes announced a state of emergency while President Luiz Inacio Lula da Silva's government offered federal support.
Firefighters are still looking for one woman who is missing after her vehicle fell in a river.
(Reporting by Gabriel Stargardter; Editing by Lisa Shumaker)
By Rodrigo Viga Gaier