Central Sydney has filled with a sea of protesters for the "Bust the Budget" march.
Organisers estimated up to 15,000 people joined the rally, which started at Town Hall and proceeded along George Street and up Market Street.
Police figures put the number of marchers at 6000.
The protest was peaceful and police said there had been no reported incidents.
Allan Jones, who attended the march with his wife, Veronica Carey, and intellectually disabled son, Ross, said he was concerned about a range of issues. "I'm ashamed to be an Australian at times," Mr Jones said.
Mr Jones singled out the treatment of asylum seekers, disability care and cuts to education and the abandonment of the Gonski scheme.
"It was a wonderful scheme. We are really disappointed about that."
Mr Jones, 79, who received an OAM in 2005 for services to people with disabilities through his work with the Pittwater-based Sailability NSW, said he also hated the secrecy surrounding the government's refugee policy.
Cody Stucker and his wife, Marisa Whitington, attended the rally with their children Freddie, 6, and Jonathan, 2.
"I'm worried about education cuts in the budget for these two," said Ms Whitington.
Mark Lennon from Unions NSW said the latest federal budget was unfair.
"Not only is it unfair, it is deliberately unfair, because this is not just about the budget, this is about a change of the agenda for this nation.
"This is about a change in the philosophical direction of the country."
The story Thousands descend on Sydney CBD to protest the budget first appeared on The Sydney Morning Herald.