The ASU-85 is a Cold War era assault gun of Soviet origin. It was developed in the 1950's as a replacement for the ASU-57 assault gun in use with Soviet airborne forces. The name ASU-85 stands for Aviadesantnaya Samokhodnaya Ustanovka, which is Russian forairborne self-propelled mount. The number 85 refers to the caliber of the main armament. The ASU-85 became operational in the early 1960's and was extensively used during the Cold War. Since the late 1960's the ASU-85 was supplemented by the BMD-1 airborne infantry fighting vehicle.

The ASU-85 is an assault gun with fixed casemate superstructure. The tracked chassis is derived from the PT-76 amphibious light tank. The crew of 4 is seated in the fully enclosed casemate. This has the long 85mm gun mounted in the middle and firing forwards. The engine and drivetrain are located at the rear.

The main armament is the 85mm D-70 L/67 cannon. This is similar to the ordnance of the D-48 towed gun and provides better range and rate of fire than the ubiquitous D-44 towed gun. The effective range is 1.2 km for armor piercing rounds and 1.6 km for high explosive rounds. The casemate structure allows for a limited gun traverse, but the tracked chassis allows the ASU-85 to pivot. Secondary armament consists of a 7.62mm SGMT or PKT coaxial machine gun. Some ASU-85 were fitted with 12.7mm DShKM heavy machine gun.

Since the ASU-85 was designed to be air dropped the weight had to be kept low. As a result the armor is quite thin. The armor protects the crew from small arms fire and shell splinters. From any angle other than the frontal arc it is vulnerable to heavy machine gun fire. Its low profile reduces its silhouette as a target.

The most distinguishing feature of the ASU-85 is its ability to be air dropped from It could also be transported by Mi-6 helicopters. The tracked chassis provides good mobility in rugged terrain. The tracked chassis allows the ASU-85 to pivot and aids in aiming the main armament. The 260 hp V-6 inline water-cooled diesel allows for a maximum speed of 45 km/h. Unlike the PT-76 the ASU-85 is not amphibious.

Due to the specific role the production number of the ASU-85 was rather low. The primary user of the ASU-85 were the Soviet airborne forces. Each division used 31 units and Poland was supplied a similar number. Eventually the BMD-1 replaced the ASU-85. Its 9K11 Malyutka missile had greater range and penetration than the 85mm gun on the ASU-85. The ASU-85 is no longer in service.