The demonstration yesterday virtually brought central Buenos Aires to a standstill amid a din of drums and chants.
Two major labour unions, the CGT and CTA, joined forces in calling the rally against the conservative president's cuts to spending and public jobs.
"The whole workers' movement is going to mobilise against layoffs, cuts and poverty, which is deepening under Macri's government," said Jose Rigane, leader of one of the branches of the CTA.
Private and public sector workers joined in yesterday's march and planned a further demonstration on Sunday to mark International Workers' Day.
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He has cut public sector contracts, raised utility prices and passed financial reforms that critics say are hurting workers' wages and spending power.
Unions say 100,000 workers have lost their jobs in the public and private sectors since Macri took office.
The government says it laid off 11,000 public workers in the first quarter of this year.
Doctors, teachers, banking employees and civil servants have staged protests over recent months.
The president suffered his first defeat this week when opposition senators approved a bill that aims to halt the layoffs. He could veto the bill but that could be politically costly.
Macri was far away from the capital yesterday in a northern region where he launched a water production program that the government says will generate 200,000 jobs.
"We are working on all the issues they are raising," he said of the protesters.