The incident happened in Blissett Street near Maidenstone Hill shortly after 5.30pm today (March 25).
Officers and London Ambulance Service crews attended and found a man who had been stabbed.
He was taken to hospital for treatment where his condition is currently being assessed.
No arrests have been made as police enquiries continue.
A spokesperson for London Ambulance Service said: “We were called at 5.43pm today (25 March) to reports of a stabbing on Maidenstone Hill, SE10.
“We sent resources to the scene including an ambulance crew, a paramedic in a fast response car and an incident response officer.
“We also dispatched London’s Air Ambulance.
“We treated a patient at the scene and took them to a major trauma centre by road.”
A spokesperson for Metropolitan Police said: “Police were called shortly after 17:30hrs on Tuesday, 25 March to reports of a stabbing in the vicinity of Blissett Street, SE18.
“Officers and London Ambulance Service attended and a man was located with stab injuries – he has been taken to hospital for treatment where he remains.
“A condition update awaits.
“A crime scene remains in place at the location.
“No arrests have been made and enquiries into the circumstances continue.”
