France was gripped by a one-day general strike on Thursday, just as Paris hosted a team of inspectors from the International Olympic Committee.
The IOC team is using a coach instead of public transport
They toured the city to assess its bid to host the 2012 Olympics.
The strike brought much of the public transport system to a halt, while tens of thousands of protesters staged rallies across the country.
All the main French trade unions took part in the stoppage to protest against government economic reforms.
The Paris bid committee kept the 13-strong inspection team away from the demonstrations.
The protests took place in the east of the city, well away from the main stadium and other venues.
The IOC's inspectors have already visited Madrid, London and New York and will visit Moscow next week.
Paris had been hoping to show the Olympic inspectors its reliable public transport system - one of the attractions at the heart of its bid.
But the state-owned SNCF rail network said only a quarter of commuter trains into Paris were running, while about half of TGV high-speed services were cancelled.
On the metro underground system, services varied from line to line, with some running virtually as normal, while others had few or no trains.
Air travel was also disrupted, with flight cancellations at Orly and Roissy-Charles-de-Gaulle airports.
The unions are protesting against government plans to reform the 35-hour week and are calling for action to boost disposable incomes.
They insist they are not against the Paris bid and say people who take part in the demonstrations will wear T-shirts and badges supporting the games.
But the BBC's Caroline Wyatt in Paris says it was the Olympic bid's worst nightmare - trade unions choosing this day, of all days, to flex their muscles.
The inspectors have visited the proposed Olympic Village site and toured the Stade de France stadium, which bid organisers have renamed Stade de France Paris 2012.
The IOC team also visited the Roland Garros tennis arena and the Eiffel Tower, where beach volleyball would be played.
The city's mayor Bertrand Delanoe put on a brave face and said the protests could be an asset - if Paris could take the disruption in its stride.
"Do you think the committee does not know what democracy means, that it doesn't know France and thinks the best countries are the ones where there are no arguments? Contrary to what people say, this could actually reinforce our bid," he said.