The Natural History Museum's collections of Diptera contains approximately 2.5 million specimens.
The Museum holds collections of International and British Diptera that are stored separately.
The international collection holds important type material of Diptera, some dating back to the 18th century, most notably of taxa described by Walker, Bigot, Brunetti, Edwards and Austen.
Parts of the world that are particularly well represented are the:
The British Diptera Collection includes donations from important collectors of the 20th century such as:
A synoptic British reference collection can be examined in the Angela Marmont Centre for UK Biodiversity.