How can I know if my father has brazilian nationality?

If in Brazil check PF. If out of country check BR Consulate. Will need full names of mother and father.

Thanks
What is PF?
Do you mean CPF?

xboss100 wrote:

Thanks
What is PF?
Do you mean CPF?

Polícia Federal - Federal Police

ok
Thanks

What makes you think that your father might have been a Brazilian?

abthree wrote:

What makes you think that your father might have been a Brazilian?

He stay's a long time in Brazil more than 25 year we've his permanent resident, but we can't find his nationality

If you have his permanent resident card, you may be able to check his RNE, his Foreigner Identification Number which appears on the card, with your local Brazilian Consulate to determine whether he was ever naturalized as a Brazilian citizen.
Brazil allows, but does not require, resident foreigners to apply for citizenship; those who do not apply are permitted to continue their resident alien status indefinitely.   A resident alien who leaves Brazil for more than two years loses permanent resident status.  If your father was never naturalized, it's doubtful that he could have passed Brazilian nationality to you.

As abthree said, RNE is just allowing to live in Brazil. If father left for over 2 years the RNE is not valid. Father would have gone thru a long process to become a citizen of Brazil.
If father has passed (Sorry for your loss if so) the RNE is no longer valid.