Young people under 16 are now banned from central Ealing after 9pm unless they are with an adult, after police decided to impose a strict dispersal order that comes into force today.
And Christmas revellers who police believe are causing a nuisance could be arrested if they refuse to leave the area when ordered, according to the new rules.
The blanket order - one of four new zones imposed around the borough in the run-up to Christmas - will last until at least March 4.
It covers the main stretch of New Broadway and The Mall, from Longfield Avenue to Northcote Avenue, and includes Haven Green and surrounding streets including Bond Street, High Street and streets behind the town hall and Ealing Broadway shopping centre.
Two more dispersal zones also came into force in today covering large swathes of Southall and the Haymill and Medway estates in Perivale, and another will be imposed on Greenford Broadway from December 13.
Ealing Council's safer communities leader, Vlod Barchuk, said: "Dispersal orders have already proved to be a vital and effective tool in trying to tackle crime and disruptive behaviour in other parts of the borough.
"This order will deal with the ongoing problems with people street drinking and intimidating members of the public.
"Every Ealing resident has the right to feel safe and not be a victim of anti-social behaviour."