Three masked marauders robbed a man inside a Queens apartment building after forcing their way into the lobby and pistol-whipping the victim, cops said Monday.

The violent robbery happened just before 10 p.m. Jan. 11 in an apartment building near the intersection of Lowe Court and 129th Street in Jamaica, police said.

Video released by the NYPD shows two of the ruffians — dressed in hoodies and face masks — crouching behind a parked car, appearing to stake out the entrance to the building.

When the 42-year-old victim opens the door, the two robbers can be seen pushing their way into the building while a third comes up from behind, video shows.

Once inside, police say, one of the brutes whacked the man in the head with a handgun.

The helpless victim can be seen being led though the building while one of the mask-wearing toughs keeps a hand over his mouth and a gun pointed at him.

Cops say the trio robbed the victim of $570 and his cellphone before fleeing north on 149th Street in a gray SUV.