A group of Las Vegas showgirls traded feathers for fists ... throwing down in a wild brawl on the Strip.

TMZ obtained a crazy video from Wednesday afternoon ... several women decked out in barely-there showgirl outfits and massive feather headdresses are right in the middle of the chaos ... swinging, shoving, and going at it as tourists look on.

And this thing gets out of control fast ... at one point, one of the showgirls charges right back into the madness and starts throwing punches ... while a shirtless man gets tangled up in the melee and people nearby scramble around the fight.

Meanwhile, those giant feathers are bouncing all over the place as the brawl spills near an escalator ... giving stunned tourists one hell of a free Vegas show.

We're told the confrontation allegedly started after the showgirls were pressuring tourists for money ... before things escalated into the full-on fight caught on camera.

We later see cops arriving after the dust -- and feathers -- settled ... with one woman still rocking her huge purple headdress while speaking with officers.

An eyewitness told us police ultimately arrested showgirls involved in the brawl.

What happens in Vegas stays in Vegas ... unless TMZ gets the video!