Hi Guys:
My daughter(Thai citizen) just received her Canadian passport. My question is if she flies out of Thailand on her Thai passport can she fly into Canada on her Canadian passport and visa versa, if she flies out of Canada on her Canadian passport, can she fly into Thailand on her Thai passport?

Thanks in advance to any feedback

She leave on her Thai passport showing both passport at check in for her flight to prove she does not need a visa for Canada. Then show only her Thai passport to departure immigration.

Then just show her Canadian passport when you gets to there.

When leaving Canada it will just be the reverse of the process.

People do this all the time.

Thanks Ubonjoe:
Great and quick info as usual.

Of course, I have 3 passports and do this all the time. A large percentage of the world's population is a citizen of more than 1 country; in Australia the ratio is one out of every four persons or around 25%.

Just show the appropriate passport at the check-in counter - you can then show the Thai passport if asked but if they don't ask don't bother. For some reason check-in staff in Thailand sometimes (though not always) like to check for Thai stamps to prove you haven't overstayed (I don't know why after all they are almost overstepping their authority) when in other countries they only ever care about the passport and visa (if required) for the country of destination but in the end all that matters at the check-in counter even in Thailand is that you can show eligibility to enter Canada.

Once at Thai immigration, the Thai passport is scanned through the auto-gates and off you go. Once in Canada, use only the Canadian passport for entering and leaving. Apparently it is illegal to use a foreign passport to enter if you are also a Canadian citizen. The law is similar in many other western countries.

However - always remember to enter and leave a particular country on the SAME passport. You can't switch passports when leaving because the other passport wouldn't have your previous visa or entry stamps in it. You can then switch to a different passport to enter another country, but only if travelling by air or sea, at least in Asia. Then again for any non-ASEAN or non-Russian related travel, you wouldn't want to use a Thai passport anyway because most other countries require visas from Thais.