The bands, who recently confirmed a joint tour together next year, took to the stage at last night's ceremony for the closing number.
The performance opened with a rendition of 'Everybody (Backstreet's Back)', followed by Backstreet's 'I Want It That Way' and New Kids' 'Step By Step' and 'You Got It (The Right Stuff)'. The show ended with a version of Backstreet's 'Larger Than Life'.
Backstreet singer Nick Carter later wrote on his Twitter account: "I want to say that I am so happy and grateful to be a part of something so special. Thank you @nkotb. I am so happy that we share the drive."
New Kids' star Joey McIntyre added on his own feed: "The show felt amazing!!! Hope u enjoyed the sneak preview!! We had fun!"
The two boybands will join forces for a string of dates together across North America next summer, starting at the Air Canada Centre in Toronto on June 9, while Backstreet's Brian Littrell has also suggested that the production could arrive in Europe at a later date.
> In Full: American Music Awards 2010 - Winners