The ETR 450 was the world's first train with active tilting mechanism that went into series production. It was developed as a result of the single-car Y 0160 prototype of 1971 and the four-car ETR 401 prototype of 1976. The bodies of the train tapered towards the top to allow for a tilt angle of up to eight degrees without interference with the loading gauge. Combined with a light axle load, this enabled the train to run through curves much faster than conventional trains, reducing the travelling times by up to 20 percent.

The outside design of the ETR 450 was similar to that of the ETR 401, and the biggest change on the inside was that power was now controlled by choppers. Each car had two traction motors, one on the inside axle of each bogie. With an output of 348 kW per traction motor, the trains reached a top speed of 250 km/h. When built each of the 15 sets consisted of six cars, what was later reinforced by two powered coaches and an unpowered dining car, resulting in nine-car trains with 16 powered axles.

Due to the unavailability of spare parts, the tilting mechanism had to be disabled in 2004 and the top speed was reduced to 200 km/h. In their last years, these trains carried a colorful livery and were used for low-cost services with only second class. All had been withdrawn by 2014 and ETR 450.03 was preserved.