Casey Crime Investigation Unit detectives are investigating an alleged armed robbery and stabbing in Hallam on Sunday afternoon, 15 January.
It is alleged a man got out of a car on Princes Highway, armed with a weapon, about 4pm and threatened three men inside another vehicle.
The man allegedly opened the car door and stabbed one of the men in the hand causing minor injuries, before stealing his mobile phone.
It is alleged the man then threatened police before fleeing the scene on foot.
The 39-year-old Dandenong man was arrested a short time later and is assisting police with their enquiries.
Anyone with information is urged to contact Crime Stoppers on 1800 333 000 or submit a confidential report online at crimestoppersvic.com.au