The incident happened in Greens End at around 2.15pm today (November 10).
Officers and London Ambulance Service crews attended and found a man, in his 20s, injured.
He was taken to hospital for treatment where his condition was assessed as critical.
No arrests have been made as police enquiries continue.
A spokesperson for Metropolitan Police said: “Police were called at approximately 14:15hrs on Friday, 10 November to reports of a stabbing in Greens End, SE18.
“Officers and London Ambulance Service attended and found a man, aged in his 20s, suffering stab injuries; he has been taken to hospital for treatment where he remains in a critical condition.
“No arrests; enquiries into the circumstances continue.
“A crime scene remains in place.
“Anyone with information that could assist police is asked to call 101 or ‘X’ @MetCC and quote CAD3558/10Nov.
“You can also provide information anonymously to the independent charity Crimestoppers on 0800 555 111.”
https://www.newsshopper.co.uk/news/23916742.greens-end-woolwich-stabbing-man-taken-hospital/