The 20-year old pop star, wearing a silver spandex suit, lit what appeared to be a large joint and took a puff after winning the Best Video award for her hit song Wrecking Ball.
Marijuana is not legal in the Netherlands, but smokers cannot be prosecuted for possessing small amounts and it is sold openly in cafes known euphemistically as coffee shops.
Cyrus opened the space-themed show on Sunday singing the song We Can't Stop, while gyrating her buttocks in the move known as twerking in the general direction of her smaller female dance partner.
To the delight of the crowd in Amsterdam's Ziggo Dome, Cyrus ended the number by sticking out her tongue, the same expression she flashed repeatedly during her eyebrow-raising appearance at MTV's Video Music awards in New York in August.
Cyrus, who long ago shed her image of innocence as the child star of Hannah Montana TV series, has made no secret of her appreciation of Amsterdam's attractions, arriving the Friday before the show and hanging out at the Greenhouse coffee shop downtown with several other stars.
She also wore marijuana leaf emblems in her earphones during a live rendition of Wrecking Ball against the backdrop of a giant video screen of herself crying.
Eminem and Katy Perry awards
The EMAs traditionally focus on global, rather than just American pop music acts, although there is a lot of overlap. Winners included Bruno Mars, who grabbed Best Song for Locked Out of Heaven, and Eminem both in the Best Hip Hop and Global Icon category.
Another notable winner was Katy Perry for Best Female Artist. Perry, apparently caught by surprise at her win, spat out a sip of champagne and took the stage to thank her fans.
During Perry's earlier performance, she hung suspended by wires as green lasers reflected off her mirrored outfit during a rendition of Unconditional.
Eminem, who has just released his first album in several years, appeared to have lost none of his rapping skill as he performed Rap God, spitting out words at a blistering pace.
He was handed his Global Icon honor by Anchorman character Ron Burgundy (played by actor Will Ferrell), who informed him that Dutch DJ Afrojack had been insulting him behind his back. "Who?" Eminem deadpanned. – AFP