The MP5 is one of the most widely used submachine guns in the world having been adopted by 40 nations and numerous military, law enforcement, intelligence, and security organisations. It was widely used by the SAS and also the American SWAT teams.

In 1980, the MP5 achieved iconic status as a result of British special forces regiment the SAS when they stormed the Iranian Embassy in London, live on television, rescuing hostages and killing five terrorists during Operation Nimrod.

Aftermarket replacement handguards with Picatinny rails are available. Single-rail models have a Picatinny rail along the bottom and triple-rail models have rails along the bottom and sides. They allow the mounting of accessories like flashlights, laser pointers, target designators, vertical foregrips, and bipods. A Picatinny rail adapter can be placed on top that locks into the claw rails. This allows the mounting of STANAG scopes and has a lower profile than the claw-rail system.