A temporary corrugated iron building was erected on the site in 1902 to provide care for victims of a smallpox epidemic that had taken place in the winter of 1901–2.

Part of the rehabilitation process involved putting the recovering patients to work in local shops, a policy which does not appear to have been entirely popular among the soldiers themselves.

[7] During the Second World War the hospital amassed expertise on the effects of crush syndrome and kidney failure as a result of treating air raid victims.

[8] The hospital was home to the first medical linear accelerator in the world at the MRC's Radiotherapeutic Research Unit, where the first patient was treated in 1953.

[9][10] The Commonwealth Building, which included the postgraduate medical school, the Wellcome Library and some research departments, was opened by the Queen in May 1966.

[13] In April 2024, Hammersmith Hospital had announced a pilot six-month trial intended to improve kidney transplant outcomes, by watching white blood cell types with donors.

A spokesperson for the Imperial College Healthcare Trust stated the change was to consolidate emergency care services in other hospitals,[20] as part of the government's Shaping a Healthier Future program.