Police were called around 2pm on Saturday 1 February to a “serious” two-vehicle collision on London Road, near to the junction with Hewett Road.
The crash involved a black Audi A1 and a green Toyota Aygo that left a woman in her 80s - who was in the Toyota - being taken to hospital with “serious, potentially life-changing injuries”, the force said.
“We would like to hear from anyone who witnessed anything of the collision, or anyone who has any dash cam footage of the incident,” a spokesperson added.
If you have any information, call 101 and quote incident number 44250048200.

1. London Road crash scene in Portsmouth
London Road crash scene in Portsmouth that left woman seriously injured Photo: Stu Vaizey

2. London Road crash scene in Portsmouth
London Road crash scene in Portsmouth that left woman seriously injured Photo: Stu Vaizey

3. Serious crash on London Road, Portsmouth
London Road crash scene in Portsmouth that left woman seriously injured Photo: Stu Vaizey

4. London Road crash scene in Portsmouth
Serious London Road crash on Saturday February 1 that left woman seriously injured Photo: Stu Vaizey