Passengers took to bikes, buses, walked, or made use of extra boat services on the Thames that runs through the city in a bid to beat the stoppage, called in protest at 800 job cuts driven by austerity measures.
The London Chamber of Commerce estimates each day the underground is shut will cost the capital's economy £48m.
The Rail Maritime and Transport union said every underground line was suspended or running a skeleton service after "rock solid" support for the walkouts in protest at staffing cuts.
The RMT said the job cuts were just "the tip of the iceberg" as the centre-right coalition government prepares 25 percent cuts in spending to tackle a record budget deficit.
However, Mayor Boris Johnson said: "Almost 40 per cent of lines have some services running."
Governments across Europe face labour unrest as they take unpopular measures to curb state spending that soared in the 2008-09 global financial crisis.
Rail and air transport, schools and postal services were severely disrupted across France by strikes and demonstrations against plans to raise the retirement age to curb a swollen public deficit.
Britain, which had to bail out its giant financial sector, is planning the harshest austerity drive in decades, with pay, job and spending cuts and pension reform looming. Ministries have been ordered to make average cuts of about 25 per cent and told to suggest budget savings of up to 40 per cent.
Thousands of members of the RMT and the Transport Salaried Staffs Association walked out on Monday evening in protest at plans to axe jobs in stations on the publicly-funded network.
Underground operator Transport for London (TFL) said, however, that services were running on a number of Tube lines and that contingency plans put in place to beat the industrial action were working.
Mike Brown, London Underground's managing director, said: "Londoners will face some disruption, but the city is not paralysed – and people will still be able to get around."
TFL said a good service was operating on DockLands Light Railway which serves the financial district in the east of the city, while the Northern Line was also largely unaffected.
Transport chiefs said additional bus services had been provided, along with extra capacity on river boat services, marshalled taxi ranks, and guided cycle rides.
Volunteers have also been stationed at bus, underground and rail stations to aid passengers and distribute walking maps.