Ronaldo made his international debut for Brazil in 1994, in a friendly match in Recife against Argentina. He went to the 1994 FIFA World Cup in the USA as a 17-year-old but did not play. He came to be known then as Ronaldinho, since Ronaldo Rodrigues de Jesus, his older team-mate on the tournament, was too called Ronaldo (and nicknamed Ronaldão to further distinguish them). Another Brazilian player, Ronaldo de Assis Moreira, who is widely known as Ronaldinho, would come to be called "Ronaldinho Gaúcho" when he joined the Brazilian main national team in 1999.
Voted the FIFA World Player of the Year in 1996 and 1997, he scored four goals and made three assists during the 1998 FIFA World Cup. The night before the final, he suffered a convulsive fit. He was initially removed from the starting lineup 72 minutes before the match but he requested to play and was later reinstated by coach Mario Zagallo. Ronaldo did not perform well and he was injured in a collision with French goalkeeper Fabien Barthez. Brazil lost the final to hosts France 3-0.
Adrian Williams, professor of clinical neurology at Birmingham University, said that Ronaldo should not have played, saying that he would have been feeling the after effects of the seizure and that "there is no way that he would have been able to perform to the best of his ability within 24 hours of his first fit -- if it was his first fit."
Ronaldo won the Golden Shoe as the top scorer in the 2002 FIFA World Cup with eight goals. He scored against every team he came up against except England in the quarter finals and scored two in the final against Germany, helping Brazil win their fifth World Cup शीर्षक. He also equaled Pelé's Brazilian record of 12 World Cup goals, adding to the four he scored in the 1998 tournament.
On June 2 2004, Ronaldo scored an unusual hat-trick for Brazil against arch-rivals Argentina in a CONMEBOL qualifier for the 2006 World Cup, scoring all three of Brazil's goals from the penalty spot, winning all the penalties himself.
In the 2006 FIFA World Cup, although Brazil won their first two group games against Croatia and Australia, respectively, Ronaldo was repeatedly jeered for being overweight and slow (Brazil President Luiz Inacio Lula da Silva questioned the national coach "Ronaldo is fat or isn't he?"). Nonetheless, coach Carlos Alberto Parreira kept him in the starting lineup in face of calls to have Ronaldo replaced. With his two goals against Japan in the 2006 FIFA World Cup, he became the 20th player ever to score in three different FIFA World Cups. Ronaldo scored in the 1998, 2002 and 2006 FIFA World Cups. On June 27 2006, he broke the all-time World Cup Finals scoring record of 14, held by Gerd Müller after scoring his 15th World Cup goal against Ghana in the 2006 FIFA World Cup Round of 16. He also equaled a much less talked about mark: with his third goal of the 2006 World Cup, Ronaldo became only the second player ever (Jürgen Klinsmann being the other) to score at least three goals in each of three World Cups. However, Brazil was eliminated by France 1-0 in the quarter-finals.
Ronaldo is currently the third highest all-time scorer of the Brazil national football team, with 66 goals. He trails second place Zico, 66, and first place pele, 77.
Following the 2006 World Cup, Ronaldo had surgery on July 16, 2006, to remove calcifications from his left tibia.

International career
Personal life
AC Milan
Popular culture