The Guaraní was conceived by Dirección Nacional y Fabricaciones Aeronáuticas (DINFIA) as a turbojet-powered, 8-seater development of the radial-engine I.A.35 Huanquero. However, the concept was dropped in favour of an even more ambitious project involving a major re-engineering of the Huanquero to create a larger aircraft, powered by French turboprops. As a result, the newly-named Guaraní had only 20% commonality with the earlier aircraft and less still after the decision was taken to abandon the twin-fin design of the Huanquero in favour of a single, swept fin. The name Guaraní was dropped at an early stage when it was found to have already been given trade mark protection; but it has stuck. Despite a concerted marketing drive by the manufacturer, Fábrica Militar de Aviones, the Guaraní was significantly eclipsed by its PT6-powered contemporaries, the Twin Otter, Beech 99 and Bandeirante, and the only orders received came from within Argentina, where it replaced the De Havilland Dove in the communications and aerial photography roles. The last active aircraft was flown from Paraná to the Museo Nacional de Aeronáutica at Morón on 7 January 2007.
First flight: 6 Feb 62 (c/n P1, LQ-HER - a fictitious registration in honour of the aircraft’s designer, Hector Eduardo Ruiz; the aircraft was not officially registered until 14 Feb 62, as LV-X23)
Production: 35, at Córdoba, CD.
First delivery: 15 Nov 66, to Argentine Air Force (c/n 01, T-154)
Last delivery: Jan 75, to Argentine Air Force (c/n 34, F-35)
Variants: I.A.50 Guaraní - prototype, with accommodation for up to 15 passengers and a twin fin design, and powered by 2 Turboméca Bastan III turboprops (1 built); I.A.50 Guaraní II – initial production version featuring a single fin and Bastan IVs, produced in passenger and aerial photography configurations (20 built, later becoming G-II; surviving aircraft underwent structural improvements and were given the unofficial designation IA-50B); IA-50 G-II - designation applied to second production batch, identical to the first (14 built).