Hundreds of thousands of demonstrators -- angry about political corruption, the high cost of living and huge public spending for the 2014 FIFA World Cup soccer tournament -- are expected on the streets of Sao Paulo, Rio de Janeiro, Niteroi, Belo Horizonte, Sao Sebastiao and other cities.
Organizers vowed to repeat what they did Wednesday, disrupting FIFA Confederations Cup matches held in Brazil as a World Cup prelude.
Spain and Tahiti are scheduled to play each other in Rio, and Nigeria and Uruguay are scheduled for a match in the northeast coastal city of Salvador.
On Wednesday, some 30,000 protesters clashed with police who fired tear gas and rubber bullets to prevent demonstrators from reaching a soccer stadium in the northeastern city of Fortaleza, Brazil's fifth-largest city. Some protesters threw rocks at police.
Several people were reported injured, including police officers.
Inside the 60,000-seat stadium, dozens of people defied FIFA rules and unveiled protest banners in the arena, the Financial Times reported.
"We want schools built to FIFA standards," one banner said, referring to high specifications set by FIFA, or the International Federation of Association Football, for stadium construction.
Demonstrators say Brazil's leaders are letting basic services such as education and healthcare languish while they spend hundreds of millions of dollars to cultivate the country's global image.
Sao Paulo and Rio officials said Wednesday they would reverse bus and subway fare hikes, with the lower fares of about $1.35 going into effect Monday.
Sao Paulo Mayor Fernando Haddad said the reversal would be a "big sacrifice" and said budget savings would have to be found elsewhere.
Rio Mayor Eduardo Paes said the lower transit fares would cost the city $225 million.
"It's not really about the price [of public transit] anymore," 18-year-old student Camila Sena told the BBC at a protest in Niteroi, Rio's sister city, 8 miles away by a bridge.
"People are so disgusted with the system, so fed up that now we're demanding change," she said.
Brazil's demonstrations began with anger over a transit fare increase. But as with many other protest movements, they mushroomed into a broader expression of anger at the government.
Paes said he realized demonstrators wouldn't "just quit protesting" because of the fare-hike reversal.
"People are protesting for more than just bus fares, and that's their right," he said in announcing the fare cuts. "We're just listening to what they're saying, and this is a way to show it."