Police in Barnet were called to Woodside Grange Road junction with Grange Way, N12 at 14:43hrs on Tuesday, 29 March following reports of a male collapsed.
Officers and London Ambulance Service (LAS) attended and found a male believed to be aged in his twenties suffering from a stab wound.
He was taken to a central London hospital by LAS and died a short while later.
Next-of-kin have not been informed. Formal identification awaits.
A post-mortem examination will be held in due course.
No arrests have been made and enquiries are ongoing.
Detectives from the Homicide and Major Crime Command are now investigating.
Any witnesses or anyone with any information can call police via 101 or give information anonymously to Crimestoppers on 0800 555 111 or at www.crimestoppers-uk.org.