A 19-year-old had a knife held to his throat and stomach by a robber who stole his bank cards and demanded the PINs.
He was walking past the Sol Central complex in Marefair, Northampton, early on Wednesday when he was pushed near the old Barclaycard building.
Police believe the victim was followed from the bottom of Gold Street.
The offender is described as white, in his late teens to early 20s, 5ft 9in (1.75m) with thick eyebrows.
He was clean shaven and slim and was wearing a vivid green pullover hooded top, which appeared too big for him, blue jeans and a black beanie-style hat.
Witnesses to the incident, between 0140 and 01530 GMT, are asked to contact Northamptonshire Police.