Thousands have hit the streets of Rome and other Italian cities, angered by reforms to the education system and conditions in the transport industry.
Three unions, representing teachers, transport and other public sector workers are striking over governments cuts to pay and jobs.
With many school children taking part, one estimate put the rally between 300,000 and 500,000 people.
One protester in Rome said: “With its indiscriminate cuts at public universities, and by making it possible to transform universities into private foundations, they are trying to block our future, the future of the university, and the future of public academic research.”
Government plans to chop 87,000 teachers’ posts have come in for harsh criticism. Protesters are also denouncing what they call lack of security in the workplace.
One commuter affected by the disruption supported the nationwide strike.
“I think these reforms are wrong and it’s time to fight back. The strike is just the first step,’‘ she said.
Despite much of Italy’s public transport system coming to a halt, a skeleton service is in place.
This is the first big stoppage Prime Minister Silvio Berlusconi has faced since coming to power 5 months ago.