In Grand Theft Auto: San Andreas and Grand Theft Auto IV, the Micro SMG is actually a civilian-legal pistol version of the IMI Micro-Uzi sub-machine gun but called Micro SMG in-game, while it is a full-sized IMI Uzi submachine gun in the other games. It can be identified as the pistol version because the side-folding wire stock is deleted, and there is no provision on the rear of the receiver to mount one. One can only assume that the pistol was illegally modified for full-automatic operation. The Micro-SMG has a respectable rate of fire, about 950 RPM, however it is slower than its real-life counterpart, which has an astounding cyclic rate of 1,250 rounds per minute. In Vice City, the Vercetti Gang carry Micro SMGs after the end of the game's storyline. The Micro SMG is also the starting weapon for the players after the regular pistol when advancing from the first points of the games.
The full sized Micro SMG was originally intended to be featured in Grand Theft Auto: San Andreas. Beta screenshots of the game show the Grove Street Families gang members perform a drive-by with the beta appearance of Big Smoke, Sweet and possibly Ryder or Big Bear. The gun was left out for unknown reasons although the animation for it from GTA Vice City was used for the MP5, when fired. The final version of the game features a Micro Uzi named Micro SMG in-game.