Anyone have US + another passport?
 

Maybe this belongs in Safety/Securtity, I don't know...

Anyway, I may be traveling to Brazil in the future, and have found out that (due to my birth in Brazil, but to US citizens) I must get a Brazilian passport. I have always traveled on my US passport in the past, but have never been back to Brazil since birth. Not a problem, and I think it's kinda cool, but some questions:

Anyone here have a US passport plus some other country? What is the method of travel? Do I use my US passport at US immigration and Brazilian passport at Brazilian immigration? This seems to make sense, but would there be problems with the stamps not matching?

I should be visiting the Brazilian consulate in the near future to get my passport... can't do it by mail.

Also, of course I would desire to be in the fastest line at any immigration - sometimes entering a foreign country it is much faster in the non-citizen line (because it is shorter). Maybe the exception being the US, as the questioning is more routine?

If it makes a difference (and appearances usually do), I am obviously not Brazilian (I'm a white male) and, to my shame, speak no Portuguese.

Thanks for any advice - I am anxious to return to my "homeland"!

there are several threads on this (search for passport and/or dual).

Upshot is you must use your US passport to leave and enter the US. Outside of that the US doesn't care whether you use a US passport or some other passport to travel into/out/between other countries.

Well, after a MORE exhaustive search, I found most of my answer:

I'm a US and Spanish dual national... I exit the US as an american, enter country #2 on whichever passport benefits me, exit country #2 (or 3, or 4, or 5) on the same passport I entered with, and re-enter the US on my US passport.

The biggest disadvantage in entering a country without using your U.S. Passport is that in case of an emergency, you may not be able to get assistance from the U.S. Consulate. In some countries, if you enter using a local passport or Identity Card, you are treated as a National of that country and denied access to U.S. Consular personnel should you need them.

Yes, that seems like one of the biggest potential disadvantages. In my case, if I go to Brazil, I don't think I would have a choice, though, it's something to have in mind, just in case.

You may also wish to ascertain whther holding a Brazillian passport may mean that you may have to fulfill certain obligations, particularly conscripted military service. A good number of years ago a colleague of mine who held dual French and British nationality nearly found himself conscripted in to the French Army for 18 months.

You do need to be careful to use your US passport when you check in for your flight if the airline scans and transmits passenger information to US immigration authorities. I did create some confusion on a recent trip from AMS to SFO by checking in with my UK passport (which I used on entry).