Do I qualify for dual citizenship? What are the rules?

[Granadabuenosaires]

If you find the birth certificate of your GF it probally says GGF, Name, last name, Italian or Naturalized Brasilian. That is no official prove but that should do the trick

[Filipe_Ghirardello]

That's it.. if you also look on the "death" document, it will also say "italian" or "brazilian naturalized". And it doesn't show in hiw Marriage certificate... it shows Italian.. I have to see the other docs.

[andrewmontone]

Hello Felipe Ghirardello after a few years I saw your post. I am Brazilian Italian and I am a lawyer in Milan.
I work with Italian citizenship. On the issue of naturalization: If it happened before or after your grandfather's birth, citizenship has already been passed on to your entire family. Don't worry. The number of naturalizations at the time were minimal. Cases of resignation and naturalization are rare. On the site I write several articles.
Montone, Andrew Lawyer website: https://www.cidadaniaitalianajudicial.com
If you need more information. Let me know.
Montone