Police have warned festival-goers to watch out for drink spiking and to drink responsibly at major festivals this year.

The Rhythm and Alps is being held between 29-31 December in Cardrona Valley near Wānaka, respectively.

In a statement, police urged people to watch their drinks at the festival.

"Don't accept drinks you haven't seen poured, the last thing you want is somebody tampering with your drink."

They also asked people to have a plan to get to and from the event safely and to protect their belongings.

"If you are taking a car to the festival, make sure all valuables are kept out of sight, all doors are locked, and the windows are up.

"Keep your phone, keys and wallet in a safe place that is unlikely to easily fall out of a pocket."

Security and police will be present at the venue.

Police said all drivers could expect to be breath-tested daily as they leave Rhythm and Alps.