Ballarat Police Criminal Investigations Unit Detective Senior Constable Garth Morris said the Polaris brand four-wheel vehicles, used for track and garden maintenance, were stolen sometime between 7pm Thursday and 3.30am Friday.

"Uniform police were called and found a storage shed had been broken into and the vehicles gone," Det Sen Const Morris said.

"It would appear they had some sort of larger suitable vehicle to load the smaller vehicles onto and it would also appear there was more than one person involved.

"It would also appear the offenders responsible had some knowledge of the presence of the vehicles."

Det Sen Const Morris said the all-terrain vehicles were housed securely and the offenders had forced a hole in the shed to gain entry.

He said the thieves had also tried to take a third similar vehicle, a Kawasaki model, but had abandoned it at the scene.

He asked for any members of the public with information about the theft to come forward.

Det Sen Const Morris said the vehicles were not used on race days and the theft was unlikely to affect the upcoming Ballarat Cup race carnival.

Anyone with information about the theft is asked to phone Ballarat CIU on 5336 6071 or CrimeStoppers, 1800 333 000.