What kind of documents do I have to show to get Vietnam visa stamped at the airport?

When holding the approval letter, you need to print it out to present to the police at your departure airport so as to board the plane. (Those who do not have the visa approval letter will be not allowed for boarding).
Moreover, please prepare these following stuffs to get your visa stamp at the airport:

• Passport (at least six months of validity upon the date of arrival)
• Printed visa approval letter
• Filled entry and exit form
• 02 passport size photos
• Stamping fee

With these things, you need to come to VISA LANDING or VISA ON ARRIVAL COUNTER after arriving to apply for Vietnam visa, then wait for Immigration Officers call your name to return your passport with a ready visa.