About 60 per cent of France's 740,000 teachers went on strike, according to union leaders, though the government put the figure lower at 39 per cent in high schools and 46 per cent in the primary sector.
Hospital workers, customs and tax officials and government employees and meteorologists have also joined in the strike.
Jean-Marc Cannon, head of the CGT union for state employees, called on Sarkozy's government to "consider the full measure of what is going on".
|Sarkozy's popularity ratings|
are at a record low [AFP]
Sarkozy campaigned for the presidency last year on a plan to trim down the civil service as a cost-cutting measure and as part of a broader plan to overhaul the state.
The president, whose popularity ratings are at record lows, made a televised speech on his education reforms on Thursday.
He said he supported the right to strike, but would push for a law forcing schools to stay open during strikes so parents can go to work.
"Strikes bring insurmountable difficulties to many families... I have asked the government to submit a bill before the summer to guarantee a right for children to be received at our schools," Sarkozy said.
In Paris, more than 50,000 civil servants, teachers, students and parents led by senior union leaders marched behind a banner that read "Together to defend and improve the public service".
Police put the figure in the capital at 18,000.
Outside of the capital, organisers said about 30,000 people turned out at a similar protest in Marseille, but police put the figure at 7,000.
In Grenoble, clashes broke out during a march of 2,000 students, as youths hurled cans and bottles at riot police who responded with tear gas.
Police blamed the violence on a small group of troublemakers.
There were also big marches in Bordeaux, Toulouse and Lyon.
Xavier Darcos, France's education minister, reiterated the government's determination to pare down the education department, the biggest ministry employing about 1.2 million people.
He said the key issue facing French education was not saving jobs, but the challenge of providing better education.
"When you have 1.2 million civil servants, it's not true that a few thousand jobs here or there is going to settle the problem," he said.