Thousands of London's iconic black cabs, many of them beeping their horns, filled the roads around Buckingham Palace, Trafalgar Square and the Houses of Parliament to the exclusion of any other vehicles.
In Paris, hundreds of drivers blocked the French capital's airports and staged a "go-slow" during the morning rush hour, while protests were also staged in Madrid, Barcelona, Berlin, Rome and Milan.
Long-running complaints about competition from private hire and unlicensed taxis have been crystallised by the new challenge posed by smartphone-dependent car services.
Uber allows customers to order and pay for a car using their phone, with geo-locating technology connecting them to the nearest taxi driver.
Unlike other private hire cabs -- those that must be pre-booked -- Uber drivers use the app to fix the fare, rather than it being calculated by a central operator.
Critics say this amounts to a meter such as those used by traditional London taxis, and say that Uber cars should therefore be subject to the same tough regulation.
But the irony of the protest is that it has provided widespread publicity for the app, and Uber has taken advantage by offering discounts during the strike.
Among those joining the protest were would-be drivers on mopeds who are learning The Knowledge, a detailed study of London street routes that every "cabbie" must complete.
"The Knowledge took me two and a half years. But then all of a sudden anyone can jump in a cab and do our job," Chapman told AFP.