The ministry will not identify the restaurant, or say which city it is in.
An official also refused to comment on the severity of the cases. A ministry spokeswoman confirmed 7 people fell ill — five Quebecers and two people from out of province.
The ministry says the cases date back to early December and that there is no risk to the public now.
Inspectors visited the restaurant in question.
Every year, there are about 100 cases of E. coli poisoning in Quebec.