A taxi driver was robbed at knife-point after he arrived in a Duston street to pick up a fare.
The driver responded to a call from Northfield Road at about 11.30pm on Thursday.
Two men got into his car and threaten him with a knife.
They stole his palmtop computer, mobile phone and money before getting out and running away down Whitefield Road, through an alley which leads to Limehurst Close.
One of the offenders was white, 5ft 6in, 20 to 22-years-old, stockily built, clean shaven, and wearing a pale grey tracksuit and a red, flat-peaked baseball cap.
The other was white, 5ft 9in, slim, about 25-years-old, with sharp features and a black jacket.
Witnesses can call Northamptonshire Police on 101 or Crimestoppers anonymously on 0800 555111.