Fans from both nations, always willing to taunt each other, have put on a show in the Olympic stands in the first days of competition in Rio.
When Argentina faced Nigeria in the basketball tournament, fans from both countries ignored the game to taunt each other.
Something similar happened a few hours earlier at the Olympic Tennis Centre, where the local fans openly rooted for Novak Djokovic of Serbia in his match against Juan Martin del Potro of Argentina.
A couple of days earlier, the Brazilians also cheered for every opponent from eventual judo gold medal winner Paula Pareto, as well as every Portugal goal in its 2-1 win over Argentina in men's soccer.
"I think it's dumb to hear the Brazilians cheering for a team that's not even in their continent," said Argentina basketball player Luis Scola of the local fans cheering for Nigeria.
"But it's also dumb that we (Argentines) are insulting them when they treat us so well when we are here." The Argentines chanted a popular song making fun of Brazil's 7-1 loss to Germany in the 2014 World Cup.
The Brazilians responded with a song making fun of Argentine soccer star Diego Maradona and his drug problems.
"I don't like when we insult the Brazilians because Brazil is not playing, besides they are celebrating seven goals from two years ago in a sport that we are not even playing right now," Scola said.
The Brazilians responded with a song making fun of Argentina soccer star Diego Maradona and his drug problems.
"I love that everybody is supporting us, but I'd rather not hear chants against Brazil," said Argentina star Manu Ginobili. "I prefer that they chant for us." Brazil and Argentina share the same group in men's basketball and will face each other on Saturday.