Noel Torres, 27, drew a knife and threatened a 43-year-old man inside the bus terminal about 6 p.m., a Port Authority spokesman said.
"Give me everything you have," Torres said, according to the spokesman.
The man handed over $8, he added.
Torres had distinctive facial piercings and was wearing a yellow and black cap, which helped the victim identify Torres to police, the spokesman said.
He was arrested inside the terminal and faced charges of robbery and criminal possession of a weapon, the PAPD said.
Editor's note: This story initially reported Noel Torres's name as Noel Lopez, based on the false name Torres gave to police.