The 42-year-old man was taken to West Middlesex Hospital as a priority, after London Ambulance Service (LAS) was called to an accident between Crown Road and Richmond Road.
A Metropolitan Police spokesman said: "Police were called at 11.01am to reports of an accident.
"A man is reported to have sustained a neck injury, which is not thought to be life-threatening of life-changing.
"The road was closed as a result before re-opening again at 12.10pm."
The incident involved a silver Volkswagen Golf and a Mercedes van.
Several bus routes were on diversion.
An LAS spokesman said: "We sent one of our ambulance crews to the scene.
"Staff treated a 42-year-old man who was collared and boarded at the scene.
"He was taken as a priority to West Middlesex Hospital."