The Canadian Food Inspection Agency (CFIA) said the move was "a precautionary measure to protect Canadians from the risk of Salmonella infection.”
Importers must now prove shipments do not originate from Iran, or they will be blocked or sent for testing.
“An outbreak investigation is ongoing, led by the Public Health Agency of Canada, with more than 100 laboratory-confirmed Salmonella infections in Canada and numerous food recall notifications linked to pistachio kernels and products originating from Iran,” read a statement by CFIA.
At least 16 people have been hospitalized, though no deaths have been reported. The Public Health Agency of Canada said 75% of cases were among women, warning that children, the elderly and pregnant women are particularly vulnerable.
The CFIA said the restrictions will remain in place until food safety reviews are complete, with penalties ranging from fines to license suspensions or legal action for violations.
Iranian pistachios have faced bans in the past.
Last year, the European Union temporarily halted imports after detecting high levels of aflatoxin, a toxic mold byproduct.
Other Iranian produce, including peppers, kiwis and potatoes, has also been rejected by Russia, India and Pakistan in recent years over contamination concerns.