Police say they are frustrated at the behaviour of Queenstown's winter revellers after almost 30 incidents - most involving alcohol - at the weekend.
More than a dozen arrests were made between Friday night and late yesterday, police said.
Many of the revellers were celebrating the start of the Queenstown Winter Festival.
But festival organisers were quick to point out none of the arrests was believed to have occurred inside organised festival events.
Senior Sergeant Keith Newell said Saturday night, in particular, was "hectic".
"[It] was extremely busy - on par with a New Year's Eve here and we are very disappointed at the number of people who were intoxicated, causing disorder, assaults, fights and drink-driving.
"We find it very frustrating."
Seven drink-driving arrests were made, Mr Newell said.
They included an 18-year-old woman who had been at the police station to see her boyfriend who was in the cells.
She was later stopped at a checkpoint at 3.20am on Saturday and found to have a breath-alcohol level of 250mcg, he said. She was returned to the station.
Police dealt with seven incidents involving disorderly behaviour and assaults in the resort, and an indecent assault.
A woman, 18, from Invercargill, was grabbed on the buttocks by an unknown male while walking in Hallenstein St about 12.30am on Saturday, Mr Newell said.
The assailant ran from the scene. He was described as being of Indian appearance and about 170cm tall.
Queenstown Winter Festival director Lisa Buckingham said she was disappointed to hear of the poor behaviour from a few people.
Organisers encouraged responsible behaviour, supplying free water and restricting alcohol sales. An estimated 10,000 people attended Friday's opening party.