The workers, represented by the CSN labour federation, began striking at 6 p.m. ET today.
Yvon Bonesso, the union's spokesman, said people are eager to settle.
"Sorry for the expression, but people are pissed," he said. "They're fed up, you know? Our guys are tired and they want a settlement soon."
Last-minute talks broke down yesterday afternoon, leaving little hope that a deal will be reached before the deadline.
Bonesso said the union is in charge of the schedule during the strike. He said it plans to increase the number of employees rather than keeping the schedule normally made by the employer.
"There will be no cut backs on services to the population. On the contrary, we might end up with more services," said Bonesso.
As an essential service, the ambulance technicians are required to provide emergency care during a contract dispute.
Bonesso said people should only call 911 during life-threatening emergencies. Otherwise, Info-Santé will be able to assist.
While picket lines could be set up, the strike will primarily affect administrative functions and the training of interns.
The ambulance workers have been without a contract since March 2010. They're seeking a revised salary scale and better pensions and benefits.
The CSN, which represents 60 per cent of the province's ambulance workers, reached a tentative deal in July, but 71 per cent of its members voted against the deal in October.Suggest a correction