The poster for the Hanoi Bike Shop featured the silhouette of a Buddha and the phrase ‘Phat Phuc…Get Your Noodle On’.
Two people complained that the advert’s slogan ‘sounded like a swearword’ when spoken, with one upset that children might see it on display.
But the restaurant said that ‘Phat Phuc’ in Vietnamese was pronounced ‘Fet Fook’ and meant ‘Happy Buddha’.
They added that the ‘Phat Phuc’ event had been running since March 2015 and was used in naming some of their noodle dishes.
The ASA decided not to uphold the complaint but acknowledged that the slogan ‘sounded similar to the expletive fuck’.
The watchdog said: “In the context of the posters, we considered that viewers who might have been offended by bad language were likely to recognise that ‘Phuc’ was from a reference to Southeast Asian language, was different from the expletive and would not necessarily be pronounced in the same way.
“We therefore concluded that the posters were unlikely to cause serious or widespread offence.”
The ASA also ruled that younger viewers were ‘unlikely’ to read or pronounce ‘Phuc’ as a swear word.
“While some older children might have pronounced it as the expletive, given the context of an ad for a Vietnamese restaurant and that the word was taken from this language we did not consider that this made it unsuitable for them to see,” the ASA said in a statement.
Hanoi Bike Shop is the latest restaurant to be challenged over its advertising in recent months.
In October London café Fuckoffee was forced to remove its ‘offensive’ sign after receiving a letter threatening legal action from the leaseholder.
Gourmet Burger Kitchen had to pull a series of posters from display around London in January after complaints that they were offensive to vegans and vegetarians .