Police on Teesside dealt with more than 900 emergency calls from members of the public on so-called "Mischief Night".
The reports, double the usual amount received, mainly involved criminal damage being caused to cars, homes and street lighting.
Cleveland Police said a minority of youngsters were to blame.
In the north-east of England, youths traditionally play pranks on the night before Halloween, some of which can get out of hand.
A police spokeswoman said: "A minority of young people seem to use so-called Mischief Night as a licence to do as they please.
"They can even see it as some sort of free-for-all. However, some of the behaviour is of a criminal nature and is complete unacceptable as well as illegal.
"The pressure of these calls draws police resources away from our fight against crime and reduces our ability to deal with emergencies."