The owners of Chai Vin et Compagnie say they had been invited to several festivals this summer.
But Quebec's liquor board, the SAQ, says it doesn't want them selling wine at festivals it sponsors.
KarineMartel, one of the wine truck owners, said they had had to pull out of four events, and might lose out on about a dozen more.
Martel said the truck can go to festivals, but they cannot sell glasses of wine inside.
She said the regulations will hurt her business and Quebec wine producers.
"We try to get people to discover, or discover again, wines from Quebec because we have absolutely amazing products here," she said. "So yes, it's hard for the business."
SAQ officials have not commented on the claim.