A short video released by the company on Friday shows a man and a woman disrobing as they stroll through the Swedish capital, eventually appearing to have shed all their clothes.
Despite looking as if they are completely naked as they saunter through Stockholm's chic shopping district, the models are actually wearing "pixel pants" long johns.
"Say 'Pixel Pants' at a Björn Borg Store in Sweden to get a pair of limited edition pixel-long johns for free," the company said in a description below the video clip.
The limited-edition long underwear line's signature characteristic is a design featuring pixellated privates, which give the impression that the wearer is naked, but has somehow had his or her genitals pixellated.
“They're a bit provocative,” one central Stockholm shop assistant told The Local, adding that no one had yet come in to claim the freebies as of 5pm on Friday.
“It's typical of Björn Borg and the customers love it. They had another joke once on some boxer shorts saying ‘Keep your balls in place'.”
Indeed, Björn Borg has a history of using edgy campaigns with lots of skin to market its products.
In 2011, an image of two naked men jumping for Björn Borg underwear drying on a clothes line proved too racy for Facebook, prompting the social media site to erase the image from Björn Borg's page.
But it appears the Swedish underwear brand has learned from the Facebook incident in its approach to launching "pixel pants".
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"Björn Borg kids are streaking around @sweden! Pixels to keep it Youtube-friendly," the company said on its official Twitter account in connection with the launch.