Originally Posted by Thai-Kiwi
Yes, but it is potentially messy. I have Thai friends who live in NZ and hold NZ passports as well as thier Thai PP. They depart NZ on NZ PP and enter Thailand on Thai PP to avoid having to get a visa, especially if on a long stay.
The entry immigration folk could rightly ask why there is no departure stamp and, more importantly for the US, why the API (Advance Passenger Information I think) is different to the departure API ('coz PP numbers would be different, even though all else is that same).
I just tell the NZ checkin staff what I am doing and they put the US passport number through the API system. The government people at AKL departures don't seem to have any problem with this. They do it all the time and know how to make it all work. As for the stamps, that doesn't matter as some countries (I can think of Cuba offhand) do not stamp passports.