Police were called at 15.34hrs on Thursday, 22 March to a commercial premises in Norbreck Parade, Hanger Lane NW10 to reports of a male stabbed.
Officers attended along with the London Ambulance Service. The victim, aged 22, was found at the scene with stab wounds.
The attacker ran off towards Lytham Grove and Cleveley Crescent.
The victim was taken to a central London hospital with stab injuries – his injuries were later deemed as being not life threatening and he was later discharged.
There have been no arrests at this stage. Officers from Ealing CID are investigating and are treating the incident as an attempted murder.
DC Leanne Ticehurst, leading the investigation, said: “This was a shocking unprovoked attack on a young man in his place of work. The victim thankfully did not sustain serious injury, but the outcome could have been far worse.
“Enquiries into the circumstances continue, and it is important that we trace the attacker as soon as possible.
“If you recognise the man in the picture, we could urge you to call us right away and give us a name.”
The man is described as a white male aged 35-45, with an Eastern European accent. He was wearing a black beanie hat, black jacket and dark boots and trousers.
If you have information that may assist the investigation, call Ealing CID on 07825 114 094 or 101, quoting 4909/22march. Alternatively, call independent charity Crimestoppers on 0800 555 111 if you could prefer not to give your name.