Police were called at 12.12am on Tuesday, 4 January by the London Ambulance Service to reports of a stabbing on the High Street in Yiewsley, uk/where/west-drayton/">West Drayton.
Officers attended and joined paramedics who were treating a man, believed aged in his 40s, who had been found with stab wounds.
Despite their best efforts, the man was pronounced dead at 00:43hrs.
His next of kin are aware. They will be supported by specialist officers.
A post-mortem examination will be scheduled in due course.
At this early stage there have been no arrests.
A crime scene is in place and some local road closures will remain while enquiries are carried out.
At this early stage, anyone who has information is asked to call 101 or tweet @MetCC, giving the reference 0063/04JAN.
Information can also be provided to the independent charity Crimestoppers, anonymously, on 0800 555 111.
