The 'You & I' singer was exiting a hotel in Bucharest, Romania with her entourage when an overzealous fan brandishing a pen snuck in through the building's entrance.
The man is then seen being grabbed by a bodyguard, who pushes him against a hard surface and throws him to the ground as GaGa makes her exit.
The Born This Way musician has relied heavily on bodyguards in the past, admitting in 2010 that she hired people to guard her as she slept after receiving "pretty ominous" hate mail.
GaGa has also been threatened by PETA recently after apparently rejecting her anti-fur stance.
In response, the star accused the animal rights organisation of running "violent, abusive, and childish campaigns".
GaGa opened up in a letter this week about being "betrayed" and dragged through "dead-beaten-horse-mud" in the last 12 months.