The ATR 72 program began in 1985, when ATR (Avions de Transport Regional) a formation between Aérospatiale (later Aérospatiale Matra) and Aeritalia (later Alenia), decided to construct a larger brother to it's already successful ATR 42. Much debate had taken place about the size of the aircraft since ATR's formation. A number of different proposed projects had ranged from the ATR XX to the ATR 62 and the ATR ST (ST for stretched). The feedback given to ATR from possible customers of the new aircraft finally manifested itself in January 1986, in the form of the ATR 72.

The aircraft was stretched 4,84m (14ft 9in) to accomodate a passenger load of 64-74 compared to ATR 42s seating of 42-50 passengers, and wingspan was increased with 2.48m (8ft 2in). Range was set to be 2,500km (1,350nm). The only external change between the ATR 42 and the ATR 72, beside the stretch is the increase in wingspan, but other changes in respect of associated systems where undertaken. Such changes included new engine mounts for the uprated Pratt & Whitney PW 120 engines and aerodynamic elements to improve lift and all-round performance, whilst greater use of composite materials helped keep the weight down. The aircraft was proposed in a -100 version and a higher gross weight -200 version, both had cargo options with enlarged front doors giving capacity for 13 standard 'BB' containers.

The prototype ATR 72, F-WWEY, made it's first flight on October 27, 1988, followed by the second aircraft on December 20. The first firm order was placed by Finnair, for 5 aircraft to be used by it's subsidary Kar Air. OH-KRA delivered to Kar Air on October 30, 1989, was subsequently the first aircraft delivered. The following year orders stood at 82 for 21 customers, many of which already operators of the ATR 42. One of the biggest orders - for 100 aircraft - was placed by American Eagle, in August 1989. First delivery took place in December 1989 to Executive Air, a Puerto Rico based subsidary of American Eagle.

Part of this so-called Super ATR 72 order, was for an enhanced verison of the ATR 72 with improved PW127 engines, giving improved take-off performance for the 'hot and high' scenario. The aircraft was designated the ATR 72-210. First delivery to American Eagle, took place in late December 1993, following FAA certification of the type.

Through the early -90ies with orders rolling in, ATR's future seemed very prosperous. A major blow to ATR came when FAA issued an Airworthyness Directive (AD), restricting operations in icy conditions. This directive came as a result of investigations into the crash of American Eagle ATR 72 N401AM on October 31 and information provided by ATR. One explanation to the crash was an "ice-induced aerodynaic aileron lock" and attention focused on trying to repeat the conditions. In all the tests performed, no situation was created which resulted in the loss of roll control when exposed to wing icing, and so the FAA eased it's restrictions.

Despite ATR's marketing efforts, sales in the US never really recovered. Although some small repeat orders were received. The ATR 72 accident, triggered the fear of the flying public for flights with turboprop aircraft over turbofan aircraft. In a way the AMR Eagle accident was the major factor in the following high sales of regional jets. Such jets have in many ways taken over routes earlier flown by turboprops, and the switch to jet equipment from turboprop equipment is evident all across the US today.

In 1993 the ATR 42-500 was launched by Mexican airline Aeromar Airlines. The new ATR 42-500 featured the PW127 engines used on the ATR 72-210, but also had some new features which led to ATR describing them as the "new generation" ATRs. The -500 incorporated changes like: New-style interior with more baggage space, lower cabin noise and vibration, 300kt cruise speed, greater payload range capability, better airfield performance, lower external noise levels, higher specification standards, maintainability enhancements. The ATR 72-210A incorporated these features into the ATR 72. The familiy commonality aspect being a major marketing tool for ATR, the ATR 72-210A changed name to the ATR 72-500 with effect from May 18, 1998. Major difference between the ATR 42/72-500 and the earlier variants, is the new high-tech 6 bladed props on the latter, while earlier variants only have 4 blades.