The ZU-23 is a towed 23mm twin barrel light anti-aircraft gun. It is the most widely employed anti-aircraft gun in the world. The design took place in the Soviet Union in the mid 1950's and it was accepted for service in the early 1960's. ZU stands for Zenitnaya Ustanovka, Russian for anti-aircraft mount. It is also referred to as the ZU-23-2. The ZU-23 is a small and simple weapon that provides a high volume of fire. For that reason it remains popular even though its usefulness against ground targets has reduced over time.

The design of the ZU-23 is based on the earlier ZPU-2 anti-aircraft gun, from which it can be distinct by the positioning of the ammunition boxes and different armament. Instead of the two 14.5mm KPV autocannon on the ZPU-2 two 23mm 2A14 autocannon. In the firing position the two wheels are raised and the firing platform rests on three outriggers. An optical-mechanical sight aids in aiming. The ZU-23 is manually operated by two men that are seated on the weapon.

The ZU-23 is fitted with two 2A14 autocannon firing the 23x152mm round. Each 2A14 is fed by a 50 round belt. The cyclic rate of fire is 2.000 rpm, but short burst must be fired to allow the barrels to cool down. The maximum effective range against air targets is 2.5 km. Ground targets, including lightly armored vehicles, can be engaged up to 2 km.

Normally the ZU-23 is towed by a GAZ-69 or GAZ-66 4x4 light truck. For increased mobility the ZU-23 is often mounted on vehicles and trucks, such as the Ural 6x6 truck. When mounted on a vehicle it is also easier to employ it against ground targets.

The ZU-23 replaced the ZPU series in Soviet service and were widely exported to nations allied to the USSR. The ZU-23 remains in active service throughout Eastern Europe, Asia, the Middle East and Africa.