Mass protestors draped in the Brazilian national flag hit the streets of Brasilia and Rio de Jenairo on Sunday to bring down President Dilma Rousseff.
President Roussef is struggling to hold on to power despite the worst recession in decades, a corruption scandal and mass demonstrations in the country.
The country is on the agenda of the whole world, with the city of Rio de Jenairo preparing to host the Summer Olympics in August.
"I am appealing for there not to be violence," Rousseff told Brazilian media late Saturday.
"I think all people have a right to be on the streets. However, no one has a right to be violent. No one," she added.
Thousands of people were already gathering in Rio and Brasilia and organisers said more than 400 cities in all would participate.
Many protesters in Rio and Brasilia came wearing the national football team shirt or with the yellow and green flag around their shoulders.
"I'm demonstrating today because I believe that only my participation can eventually stop the mismanagement of the country's riches," said Marcelo Antunes, 66, an engineer in Rio de Janeiro. "I think all Brazilians need to participate -- we can't stand aside."
President Rousseff has been hit by a giant corruption scandal centred on the state oil company Petrobras and her management of the recession faces impeachment in Congress.