Police were called at 6.25pm on Tuesday, 9 March following reports of a stabbing in Fentiman Road, SW8.
Officers attended with London Ambulance Service paramedics. A male, believed to be aged 17, had sustained stab wounds and was taken to a south London hospital.
His injuries are not believed to be life threatening at this stage.
A crime scene is in place and enquiries are ongoing. The public can expect to see additional officers in the area in the coming hours.
Anyone who witnessed the incident or who has relevant information should call 101, using the reference CAD6013/08MAR.