Officers from the Serious Collision Investigation Unit are appealing for witnesses following a fatal collision in Isleworth.
Police were called to Twickenham Road, TW7 at approximately 13:15hrs on Thursday, 26 April to reports of a road traffic collision between a Toyota and a moped.
The 18-year-old rider was treated by the London Ambulance Service but died at the scene at 13:59hrs. His next of kin have been informed.
A post-mortem examination will be scheduled in due course.
The driver of the Toyota stopped at the scene.
Officers from the Roads and Transport Policing Command are investigating.
Any witnesses or anyone with any information is asked to contact detectives at the SCIU on 020 8543 5157 or via Twitter @MetCC quoting reference 763/26Apr.
There have been no arrests and enquiries continue.