The tent was worth about $2000.
A toolbox and a canvas canopy were also taken from the vehicle.
Const Bruce McLean said the theft was believed to have occurred after 1am yesterday and was reported at 9am.
The tent was so heavy two people would have been needed to lift it.
At 10m by 4m, the tent would stand out "well and truly" once erected.
However, the sides were left behind, Const McLean said.
"Naturally, Speight's [the owners of the tent] are highly disturbed as this is an expensive unit and was used for the Perfect Woman competition.
"This act of theft may have an effect on the event being held again here as the sponsorship from Speight's is crucial and they may reconsider supporting it again. We want it back," Const McLean said.
The Luggate Volunteer Fire Brigade and Wanaka police attended a car fire on State Highway 6 near Wanaka Airport about 8.05am yesterday.
Senior Constable Ian Henderson said the car belonged to a Timaru couple, who were unharmed.
The car was badly damaged.
