Police are baffled as to how a man ended up in a Melbourne hospital with gunshot wounds to his arm and abdomen.


Armed Crime Task Force detectives are appealing for information about the shooting, believed to have occurred in Melbourne's northern suburbs on Tuesday night.


The 21-year-old Greenvale man was driven to the Northern Hospital by another man aged 26.


The injured man is now in a stable condition in the hospital.


The driver was interviewed by police before being released pending further inquiries.


Police said the exact circumstances of the shooting are unknown, but believe the shooting may have occurred in the Tullamarine or Westmeadows area.


Detectives are trying to establish a crime scene and believe a 2003 black Ford Fairlane sedan, with personalised number plates, NARJEC, may have been used during the shooting.


Anyone who may have seen this vehicle or heard a gun shot on Tuesday night should contact Crime Stoppers on 1800 333 000 or www.crimestoppers.com.au