The foreign service officers have been on strike for four months, but this was the most extensive disruption yet of visa services.
The action involves Canada's biggest visa processing centers at 15 embassies and consulates around the world.
They include centers in Paris, London, Moscow, Mexico City, Cairo, Abu Dhabi, Riyadh, Ankara, Beijing, Delhi, Chandigarh, Hong Kong, Shanghai, Manila and Sao Paulo.
The Professional Association of Foreign Service Officers, which represents the strikers, said it decided on the action after government negotiators rejected binding arbitration.
The agents are seeking salary parity with other federal government employees.
"We take no pleasure whatsoever in these strike actions and their real, severe, and mounting effects on the Canadian economy," the association, which represents 16,000 active and retired foreign service officers, said.