Police have taken action against more than 408 people at the Cambridge Strawberry Fair at the weekend.
A Cambridgeshire Police spokeswoman said 240 people were given formal warnings for cannabis possession and 73 people were arrested.
Eight people were given penalty notices for urinating in public and British Transport Police dealt with more than 75 people, she said.
The annual fair is a festival of music, entertainment, arts and crafts.
The event is held at Midsummer Common.
Out of the 73 arrests by police officers, 46 were given street bail, where suspects appear at a police station at a later date rather than at the time of arrest.
Supt Simon Megicks, who led the police operation, said: "The weekend was very busy and officers worked hard to help make this an enjoyable, safe event.
"We took action against people who flouted the law. It is a disappointment that there were over 400 prosecutions.
"I am very pleased with the resources we had in place to deal with community issues outside of the event, which had a knock-on effect on local residents."
Last year there were 300 drug seizures, the majority of which was cannabis the police spokeswoman said.
She added 38 people were arrested for drugs and public order offences and 20 people were given fixed penalty notices for urinating and defecating in the street.