About 1,000 people gathered in Rome, while several thousand were in Milan, where demonstrators wore badges with a yellow star and the inscription “I have not been vaccinated”.
About 100 opponents of child vaccination gathered in Naples.
A sanitary pass, which includes proof of vaccination, past illness, or a negative test for the coronavirus, is mandatory from Friday to enter museums, cinemas, indoor sports halls and restaurants.
From September 1, that pass will be mandatory for staff in schools and universities, and for students. It will also be mandatory for domestic flights and longer train journeys.
In Italy, more than 128,000 people have died from the corona virus.