The incident happened in Foxley Hill Road at around 9am this morning (November 4).
Ambulance crews and a clinician in a response car were dispatched and a woman was treated at the scene before being taken to hospital.
Goodstone Road which is adjacent to Foxley Hill Road remains closed both ways between Dale Road and Foxley Hill Road and between Kenley and Purley Cross.
Detours are in operation for bus routes 407, 412, 434 and 439.
A spokesperson for London Ambulance Service said: “We were called today (November 4) at 8.56am to reports of a car in collision with a pedestrian at Foxley Hill Road, Purley.
“We sent resources including ambulance crews and a clinician in a response car.
“We treated a woman at the scene before taking her to hospital.”
