The incident happened in Leyton High Road near BP station just after 4pm yesterday (May 11).
Officers and London Ambulance Service crews attended and found a man who had been stabbed.
He was taken to hospital for treatment where his injuries were assessed as non life threatening.
No arrests have been made as police enquiries continue.
A spokesperson for Metropolitan Police said: “At 4.06pm on Sunday, 11 May police and the London Ambulance Service responded to reports of a stabbing on Leyton High Road.
“A 46-year-old man was taken to hospital. His injuries were deemed non-life-threatening and non-life-changing.
“The road was closed in both directions and has since been reopened.
“At this stage, no arrests have been made and an investigation has been launched.
“If you have any information that may assist please contact police by calling 101 and stating 4750/11MAY.”
A spokesperson for London Ambulance Service said: “We were called at 4.05pm yesterday (11 May) to reports of an assault in High Road, Leyton.
“We sent an ambulance crew and a paramedic in a fast response car to the scene. The first paramedic arrived in less than three minutes.
“We treated on patient for an arm injury and took him to hospital as a priority.”
