Police received a call from London Ambulance Service at 2.28pm on January 12, reporting a car hitting a male pedestrian on A4.
The pedestrian, in his 60s, was pronounced dead at the scene.
No arrests have been made yet as officers work to inform the man’s family.
Witnesses are urged to share any relevant dash cam footage to facilitate the ongoing investigation.
Any witnesses, or those who have dash cam footage of the incident or moments leading up to it, are asked to call 101 ref CAD 3609/12 Jan.
A spokesperson for Metropoliton Police said: “An investigation has been launched following a fatal collision in Hounslow.
“Police were called by London Ambulance Service at 14:28hrs on Friday, 12 January to reports of a collision involving a car and a male pedestrian on the A4, at the junction with Springwell Road, Hounslow.
“Officers responded with LAS and London’s Air Ambulance.
“Despite the best efforts of emergency services, the pedestrian, aged in his 60s, was pronounced dead at the scene. Police are working to inform his next of kin.
“There have been no arrests.
“Any witnesses, or those who have dash cam footage of the incident or moments leading up to it, are asked to call 101 ref CAD 3609/12 Jan.”