[1] As a player, he was a centre-back who began his career at Guarani and went on to spend most of his playing years in Europe, notably for Benfica and Beşiktaş.

Born in Piracicaba, São Paulo, Ronaldo started playing with Guarani, moving to Atlético Mineiro shortly after.

Benfica in Portugal, backing up Jorge Bermúdez and Hélder Cristóvão in his first season but became the club's first-choice afterwards as they failed to win any silverware.

In the 2002–03 season, he only missed one match in the Süper Lig as the Istanbul team won the title after eight years.

Ronaldo represented the bronze medal-winning Brazil squad at the 1996 Summer Olympics, playing in all matches.