The incident took place in Paulsgrove earlier this month, police said in a statement today.
The victim had stopped to speak to a man he knew outside St Kitts House, in Hillsley Road, on Saturday, January 9.
While chatting, a thief approached the pair and then snatched the electric scooter, riding off with it.
Then a day later, the victim spotted his scooter being ridden towards St Kitts House by the thief at 8pm.
A spokesman for Hampshire Constabulary said: ‘The victim has seen the same person riding the scooter and a foot chase has ensued towards St Kitts House.
‘This resulted in an altercation between the victim and two men, one of whom assaulted the victim by punching him in the back of the head and the other threatening the victim with a knife.
‘This caused him to fall back and suffer minor injuries – including a cut to his hand.
‘The two men have then fled the scene, taking the scooter with them.’
Portsmouth attempted murder victim ‘stable’ as man, 18, released on bail by poli…
The scooter has been described as a Honey Whale stand-on electric scooter, black with two orange stripes on the base, lights on the front, back and along the side and large mud guards.
Detectives have now released an e-fit of the suspects and are appealing for information.
A police spokesman added: ‘Were you in the area at the time? Did you see what happened? Perhaps you’ve been offered a scooter matching the description?’
Anyone with information relating to this incident is asked to call 101, quoting 44210009680.
Alternatively, you can contact independent charity Crimestoppers anonymously on 0800 555 111.