The GSh-18 is a modern pistol of Russian origin. It was designed in the 1990's as a replacement of the Makarov PM standard issue pistol in use with Russian military and law enforcement. The pistol is named after the intials of its designers and the magazine capacity. During military trails the Pya design was selected and it remains to be seen if the GSh-18 will receive significant orders.

The GSh-18 is recoil operated pistol with a locked breech. Locking is achieved by a rotating barrel with the unique amount of 10 locking lugs that require only a very limited rotation. The GSh-18 is striker fired and features a trigger safety. The frame is made of polymer and the barrel, slide and internal mechanism out of steel. A staggered row 18 round magazine is used.

The GSh-18 fires the 7N31 armor piercing high pressure version of the 9x19mm NATO round from an 18 round magazine. Standard 9x19mm ammunition can also be used. The GSh-18 is a self-loading weapon and is only capable of semi-automatic fire. The 7N31 round has a much better armor piercing capability than standard 9x19mm ammunition and will pierce level III body armor at 20 meters. Military trails have shown that the GSh-18 is very reliable.

The GSh-18 lost out to the PYa to become the next standard issue sidearm for the Russian forces. Therefore it remains to be seen if this good design has any future. The GSh-18 is reportedly in very limited use with various Russian law enforcement or military units.