Ten of Paris's 16 lines were shut and service on the others was disrupted. Many workers cycled, walked or stayed at home, while free rides were on offer on transport operator RATP's e-moped and Uber's e-bike and scooter networks, the BBC reported.
The strike the biggest since 2007 is the first big act against President Emmanuel Macron's plan for a universal pension. It would replace dozens of different pension schemes for different professions.
Members of other professions including lawyers, airline staff and medical workers have called for more strikes starting on Monday.
There were 235 km of traffic jams in the Paris region, officials said, over double normal levels. Media reports showed photos of crammed platforms on four metro lines, where some trains were running.
Le Parisien newspaper said a legal requirement to maintain a minimum level of service in place following a big strike in 2007, which was also against a pension overhaul was not being fulfilled.
RATP's three main unions called the strike a "shot across the bow" for Macron's reform plans. Metro workers say the new universal pension would force them to work longer by taking away their right to retire early, negotiated decades ago to compensate for having to work long hours underground.
On an average, Metro workers retire at 55 while most French workers retire at 63.
The move to a universal points-based pension system would also remove the most advantageous pensions for a range of jobs ranging from sailors to notaries and including Paris opera workers.
Meanwhile, those retiring before 64 would receive a lower pension. For example, someone retiring at 63 would receive five per cent less.
On Thursday, Prime Minister Edouard Philippe insisted the reforms would be fair for everyone. "We're going to construct a truly universal system where every euro paid in will provide the same rights for everyone, whether a labourer, a shop owner, a researcher, a farmer, a civil servant, a doctor or an entrepreneur," he said.
The French government wants Parliament to vote on the plans early next year.
( With inputs from IANS )