Following prolonged studies Aermacchi flew the prototype MB-339 trainer on 12 August 1976. The type was developed from the company's previous successful MB-326 design; the chief modification compared with the MB-326 was the redesign of the tandem cockpits to give the instructor a good view ahead over the helmet of the pupil. Directional stability was maintained by a larger fin and canted ventral fins, and standard equipment included the Viper Mk 632 engine and Mk 10F zero/zero seat.
The first of 100 MB-339A trainers for the Italian air force (AMI) was handed over on 8 August 1979. Other AMI variants include the MB-339PAN of the Frecce Tricolori aerobatic team and the MB-339RM calibration aircraft. In addition, aircraft generally similar to MB-339A standard have been widely exported to customers which include Argentina, Dubai, Ghana, Malaysia, Nigeria, Peru and the UAE.
Aermacchi also produced the MB-339B, with upgraded advanced MB-339C. Variants of the MB-339C include the MB-339CD for advanced/fighter lead-in training and its MB-339FD export equivalent, with a fully digital cockpit, and the MB-339CB which has been delivered to New Zealand. Eritrea received six MB-339E non-digital variants of the MB-339C.
Developed in 1995 from an MB-339A, the MB-339AM is a variant specialized for anti-ship attack and armed with two Marte Mk 2A missiles. On 30 May 1980 the prototype MB-339K Veltro 2 entered flight testing. The forward fuselage was broadly similar to that of the MB-326K with a single-seat cockpit and two 30-mm guns below. Advanced avionics, comprehensive weapons compatibility and a rugged airframe failed to tempt customers, however, and the variant was quietly dropped.