Detectives said they were called to reports of five men fighting in Park Road, Norbiton, just before midnight on Monday.
An injured man made his own way to Kingston Hospital where he has since been discharged.
Officers believe he may have been the victim of a robbery.
The suspects made off from the scene shortly afterwards.
No arrests have been made and enquiries continue.
Anyone who witnessed the stabbing or has any information is asked to contact detectives at SW CID on 101 quoting reference CAD 8499/12AUG