Police have used new powers to move on youths and street drinkers 25 times since the beginning of the month.
A dispersal zone came into force in the centre of Harrow on August 1 following an agreement between the council and police.
The power allows officers to disperse groups of more than two and order teens under 16 to return home.
If they return within 24 hours they can be arrested.
The zone currently covers Harrow on the Hill Station, Greenhill Way,Sheepcote Road, Kenton Road, Peterborough Road, Bessborough Road and West Street.
Sergeant Mike Windeatt of Harrow police said: "The dispersal order has been very effective in moving on groups who are causing a disturbance or who we suspect might make others anxious.
"It is particularly useful over the summer when more people are likely to be in the town centre for longer periods."
Councillor Susan Hall, Harrow Council's deputy leader and portfolio holder for environment services, said: "Along with the extension of the alcohol exclusion zone, this dispersal order has been an important next step in giving our police service more powers to address anti-social behaviour.
"Harrow is one of the safest London boroughs and we want people to know they can enjoy our town centre safely either by day or night."