In Barcelona, protesters blocked a main road for an hour; in Valencia they blocked a port. Here in Madrid, a crowd packed the street outside the economy ministry banging saucepans and drums and shouting slogans.
Spain's two main trade unions called a strike across the public sector on Tuesday to protest against an average 5% cut in pay.
It's part of the 15bn euro (£12bn; $18bn) austerity package introduced by the government late last month in an attempt to cut a budget deficit swollen by almost two years of recession.
The government describes the austerity measures as the only possible choice for a "responsible" party of power.
But many public sector workers believe the cuts are the result of the government's mismanagement of the economy, specifically its failure to acknowledge the extent of the crisis here early on.
Many banners at the protest denounced the government as "irresponsible".
"We are not responsible for this crisis," one read. "We're not the ones who'll pay for it."
"It's always us who make sacrifices," fireman Luis Miguel Egea explained, outside the economy ministry.
"When times are good, workers in private companies are paid bonuses while we get nothing. When things go bad, we're the only ones who face pay cuts."
A minimum staffing requirement meant the fire service, schools and hospitals continued to operate throughout the walkout.
Public transport was almost unaffected, reducing any disruption.
But at some universities, summer exams had to be postponed as professors joined the protest.
"Most people agree the government needs to cut the deficit, but it should be done in other ways," says university law lecturer Angel Manuel Moreno.
"Public sector workers are one of the few groups that can make savings in Spain, because we have fixed salaries. We have mortgages. We buy houses, cars. Cutting our salaries, will stop spending, and harm the economy," he says.
Test of resolve
But the government argues that tough medicine is essential to treat Spain's worst economic crisis in decades.
After avoiding unpopular decisions for many months, it now sees spending cuts and sacrifices as inevitable to help the economy back to growth.
"Of course no-one likes to have their wage cut. But it's also true that civil servants have a job for life, while many other workers are suffering the consequences of the crisis," points out Juan Moscoso, member of parliament from the governing Socialist Party (PSOE).
The unemployment rate in Spain is twice the EU average, currently hovering around 20%.
But the cut in public sector pay represents a U-turn in policy for the Socialists - which is why many suspect it was unavoidable.
Crucially, unlike in Greece, the government has not announced the far more painful measure of major redundancies.
And a recent poll published in El Pais newspaper showed 58% support for the public sector pay cut.
"I am against this strike," lawyer Alberto said, watching protesters with trade union flags pass him by in central Madrid.
"I think the whole country is suffering from the economic crisis. The public sector should be more aware of all of us."
Still, many worry that more, even more painful cuts are on the cards.
A proposed labour reform - introducing more flexibility in the labour market - will be deeply controversial if the government presses ahead without consensus.
The unions are already threatening a general strike.
This time, organisers claim up to 75% of public sector workers took part; the government estimate is close to 11%.
So what did it achieve?
"The government is very committed to these measures, though it knows they are difficult," PSOE deputy Juan Moscoso explained.
"But we need to take them in order to return to growth and recover. If not, we will be in deep trouble."
That resolve - slow to form - will be sorely tested in the weeks and months to come.