Firefighters were called to a road traffic collision in Thames Street in Hampton.
A car and a van were in collision.
Four people left the car before the Brigade arrived and firefighters released one woman from the van. All five were taken to hospital by London Ambulance Service crews.
Crew Manager Tim Lucas, who was at the scene, said: "Crews stabilised the van and then cut away the door to allow paramedics to gain access.
"They assisted them with extracting the casualty and she was then taken to hospital along with the four people from the car."
The Brigade was called at 1504 and the incident was over for firefighters by 1541. Two fire engines from Twickenham and Feltham fire stations and a fire rescue unit from Heston fire station attended.