Police say the City Sights New York employee was standing in front of the Toys R Us store when he got into a dispute with a man around 7:30 p.m. Thursday.
The ticket seller was then stabbed in the arm at the intersection of 44th Street and 7th Avenue in front of a huge crowd of tourists.
The victim was taken to Bellevue Hospital with non-life threatening injuries.
It's not clear what the argument was about.
Police arrested the suspect about an hour after the attack.
