Fire crews from Dee Road station removed the roof of a light blue BMW to free the woman who had neck pain after a collision with a black BMW in Waverley Road, Tilehurst at 12.45pm.
The woman was taken out of her car on a back board and taken to hospital as a precaution. It is not known what injuries she had.
The man in the black car was unhurt.
The road was closed for about an hour and 15 minutes while firefighters and paramedics removed the woman from the car.