After campaigning the Diablo SV-R for four years in the Diablo Supertrophy, Lamborghini launched a completely new car for the 2000 season. Just as the SV-R was a race-ready SV, the Diablo GTR, introduced at the 1999 Bologna Motor Show, converted the already impressive Diablo GT into a track machine with power improvements, a stripped interior, and weight reduction.
 
The GTR interior was stripped down to save weight; the air conditioning, stereo, and sound and heatproofing were removed, and a single racing seat with 6-point seatbelt harness, MOMO fire suppression system and steering wheel, complete integrated roll cage, fixed Plexiglass windows with sliding sections, and fresh air intake were fitted.
 
The GT had already featured a radically styled body, but the GTR took this a little further with features such as a very large rear spoiler bolted directly to the chassis like a true race car, 18 inch hollow magnesium Speedline centerlock wheels, pneumatic air jacks for raising the car in the pit lane (like the SV-R, it was too low for a rolling jack), and an emergency fuel shutoff switch on the left front fender.
 
The GTR utilized the same basic 6.0 liter V12 engine that had made its debut on the street-legal GT, but with revised fuel and ignition systems, individual throttle bodies, a dynamic air intake duct system, variable valve timing, titanium connecting rods, and a lightened crankshaft. These improvements allowed the engine to produce 598 PS (440 kW; 590 hp) and 640 N⋅m (472 lb⋅ft) of torque. The engine was bolted to the usual 5-speed transmission in a rear-wheel drive layout. Extra heat exhangers were added for the differential and transmission oil to prevent overheating under extreme racing conditions. A fast-filling racing fuel cell replaced the standard gasoline tank. The suspension was stiffened and lowered, and racing brake calipers were installed.
 
Thirty cars were planned, 40 were built, and 40 chassis were prepared to replace cars wrecked in racing accidents.
 
In the hands of multiple Australian Drivers' Champion Paul Stokell, a Diablo GTR run by Team Lamborghini Australia won the 2003 and 2004 Australian Nations Cup Championships. The GTR was also raced by Stokell, Luke Youlden, Peter Hackett and Danish driver Allan Simonsen in the 2003 Bathurst 24 Hour race where after qualifying 6th would go on to finish 8th outright after suffering a number of punctures throughout the race.