Police said Juan Mendez-DePaz allegedly walked up to the drive-through window on Sunday just after midnight and demanded burgers or he would shoot them with the two guns he told them that he had under his jacket.
Police said workers quickly closed the drive-through window and called 911.
Southampton and state police arrived on scene and said they were able to locate the man, who was described as wearing a black cowboy hat and black vest, and was still in the McDonald's parking lot.
Police said after a search of the man, they found he was not carrying guns, but was in possession of a knife.
Cops charged Mendez-DePaz with criminal possession of a weapon in the fourth degree, a misdemeanor, and robbery in the 1st degree, a felony.