The A8 debuted in Europe in 1994, although it wasn't until 1997 that it became available in North America. Unlike the V8 model, which was built on an existing steel platform, the A8 debuted on Audi's then-new D2 platform, an all aluminum space frame which helped to significantly reduce weight without being any less rigid. The sedan was offered in both the A8 and the A8L long-wheelbase version. The A8L has 5 inches of additional wheelbase, which are entirely devoted to rear-seat space. In addition to being the world's first car built on an entirely aluminum platform, updates to the car in 1997 included the addition of six interior airbags, making the A8 the first vehicle to be so equipped.

For 1997, the new A8, in addition to being available in short and long wheel base forms, is available with front-wheel drive or all-wheel drive Quattro. The front wheel drive model is powered by a 3.7L V8 producing 230hp while the Quattro receives Audi's 4.2L V8, which produces 300hp. Being a luxury car, the A8 includes all the standard amenities seen in cars of its class like dual-zone climate control, real wood and leather interior, 14-way power and heated seats, and a premium Bose audio system. Audi's flagship received a few tweaks for 1999 with new colors and restructuring of option packages. The warm weather package was now offered with a solar sunroof that would allow the car to turn on the air conditioning or heating without turning on the motor of the car. Changes to all models included a regular sized passenger mirror in lue of the small one that had been offered on all Audi's previously and a first aid kit located in the rear armrest.

The 2000 model year saw front-end re freshening with new, larger, clear headlights, a revised grill, and lower front valance with standard projection fog lamps. On the interior, the seats received a new, horizontal stitch pattern instead of the many vertical lines. Also, the 3.7 Liter front-wheel drive model was dropped leaving the 4.2 Quattro and 4.2L Quattro to continue on. The main difference between the two models now was the added 5 inches of rear legroom, a navigation system which was available on the 4.2, and heated rear seats.

For 2001, A8 received minimal changes, the biggest being the added SIDEGUARD side curtain airbags. The big news in 2001 came when Audi introduced their new W12 engine, a compact 6.0 L unit developed by mating two 3.0 L VR6 engines together at the crankshaft, similar to the 3.6 L engine from the V8 model which had been created by mating two inline-four cylinder engines at the crankshaft. The engine quickly became available in the A8, although only to European and Asian customers. From its introduction through its discontinuation in 2003, only 750 of the W12 models were produced.

The 2002 model once again saw minimal changes with the anticipation of an all new design that fall. The main changes were in options and features. The A8L was now standard with Xenon headlights and a heated steering wheel. A few new options were added like a tire pressure monitoring system and new exterior colors.

In 2001, Audi introduced in the U.S. market an S8 variant in the vein of Mercedes-Benz AMG models. Although it shared the standard model's platform, it featured a re-tuned, 360 PS (265 kW) version of the standard V8 engine, a re-tuned suspension with larger wheels and upgraded tires, enlarged brakes and a re-calibrated version of the 5-speed Tiptronic transmission (European-spec. models had a 6-speed manual transmission option); quattro was standard. Production of the first-generation S8 ended in 2003, shortly before the introduction of the D3 platform A8.