The incident happened in Markhouse Road near Ringwood Road just after 10.40am today (March 28).
Officers and London Ambulance Service crews attended and a woman was found injured.
She was taken to hospital for treatment where her condition is unknown.
Markhouse Road is closed both ways between Ringwood Road and St James Street near South Grove.
Bus routes 58, 158 and W19 are on diversion as the incident is being dealt with.
We have contacted Metropolitan Police for further information.
A spokesperson for London Ambulance Service said: “We were called at 10.41am today (28 March) to reports of a road traffic collision on Markhouse Road, Walthamstow.
“We sent an ambulance crew and a paramedic in a fast response car to the scene.
“We treated a woman at the scene and took her to hospital as a priority.”
