The incident happened at the junction of Messina Avenue at 3.10pm today (July 31).
Emergency services attended and man was found who had been stabbed.
He was taken to hospital where his injuries were assessed as life-threatening.
Earlier today, a London Air Ambulance landed at Kilburn Grange Park.
A crime scene is in place near Messina Avenue as police investigate.
A London Ambulance Service spokesperson said: “We were called at 3.10pm today (31 July) to reports of a stabbing on Kilburn High Road, NW6.
“We sent resources to the scene, including an ambulance crew, an incident response officer and a paramedic from our tactical response unit. We also dispatched London’s Air Ambulance.
“We treated a man for stab wounds and took him to a major trauma centre.”
A Metropolitan Police spokesperson said: “Police were called at 15.09hrs on Thursday, 31 July to reports of a stabbing on Kilburn High Road, NW6.
“Met officers attended the scene alongside London Ambulance Service and London’s Air Ambulance, where they found a 19-year-old man, suffering from stab injuries.
“He was taken to hospital where his condition has been assessed as life-threatening.
“A scene is in place while police investigate the circumstances.
“No arrests have been made at this time.”
Anyone with information is asked to call the police on 101 quoting CAD 4615/31JUL. Alternatively, contact Crimestoppers anonymously on 0800 555 111.
