Otago University students ran wild in Dunedin on Tuesday night, in an annual toga parade in the central city.
At the height of the parade, about 2000 students clad in togas were involved in the disorder.
Eggs, rubbish and glass were strewn along the main street and windows were smashed in cars and shops.
Three arrests were made for breaches of the peace during the parade.
Police say the parade may have been well organised to start with, but the numbers who turned out were larger than expected.
Dunedin City Council member Dave Cull says the city may have to stop future student parades.
He told Morning Report some serious questions need to be asked.