Police were called to Cleeve Road at around 11.30 last night.
A man was taken to hospital with what are believed to be serious injuries.
Police say it is believed he was attacked by 3-4 men, who are described as in their late teens and dressed in black.
The road is closed at the junction with Randals Crescent while officers carry out further enquiries and will remain so for the time being.
Detective Inspector Jo Horner, who is leading the investigation, said: “We appreciate that the road closure is inconvenient for local residents, particularly people trying to access the nursery school, and we want to reassure you that we are doing everything we can to progress our enquiries and ensure that the cordon is lifted as soon as possible. I want to thank the local community for their patience while we go about doing this. If you have any information or concerns about what has happened, our officers will be in the area today and will be happy to do what they can to reassure you.”
Anyone with information should contact Surrey Police on 101 quoting reference PR/45240044610.
