The PT-76 has an ideal design for amphibious capability, but both has a number of limitations as a fighting vehicle. It's amphibious design with a boat-like hull and limitations in weight allowed less armor protection. Tank's thin hull is vulnerable to 12.7-mm machine guns and artillery fragments. Later production vehicle were fitted with an automatic fire suppression and NBC protection systems.

It is armed with a 76.2-mm gun. It has a maximum effective range of fire in 1.5 km and rate of fire of 7 rounds per minute. By modern standards this gun is considered light, but is still capable of penetrating APCs and other light armored vehicles. A total of 40 rounds are carried for the main gun.

Secondary armament consists of coaxial 7.62-mm machine gun. Some tanks were fitted with a 12.7-mm anti-aircraft machine gun on top of the roof.

Vehicle has a crew of three, including commander, loader and driver.

The PT-76 is powered by a V-6B diesel engine, developing 240 horsepower. Vehicle is fully amphibious without additional preparation. It is propelled on water by two waterjets. Auxiliary fuel tanks can be installed for longer operational range.

Variants

PT-76 Model 1 with a D-56T gun;

PT-76 Model 2 with a D-56TM gun;

PT-76 Model 3 with a D-56TM gun;

PT-76B, fitted with new fully-stabilized D-56TS gun, improved observation and communication equipment. This variant replaced the original PT-76 in 1959;

PT-76M, featured improved seaworthiness and was intended for naval infantry units. However this light tank was not accepted to service and Soviet naval infantry were armed with the PT-76B;

Polish PT-76 variant features a separate commander's hatch and a 12.7-mm anti-aircraft machine gun;

Type 63, variant of the PT-76 produced in China. It has a new turret with a 85-mm gun;

BTR-50P armored personnel carrier;

ZSU-23-4 Shilka self-propelled anti-aircraft gun;

ASU-85 airborne assault gun;

FROG-2 and FROG-5 missile launching vehicles;

SA-6 Gainful surface-to-air missile system.