Work began on the IAR 80 prototype in late 1937, originally with an open cockpit and the IAR K14-III C32 engine which was a licensed Gnome-Rhône 14K II Mistral Major. The prototype was completed slowly, and first took to the air in April 1939. Test flights of the prototype were impressive; the aircraft could reach at , service ceiling of with the ability to climb to in 6 minutes, which was respectable at the time, though not up to the contemporary Supermarine Spitfire or Messerschmitt Bf 109 fighters. In comparison the P.24E was almost 450 kg lighter, yet over 80 km/h slower with the same engine. The IAR 80 also proved to be enjoyable to fly and was maneuverable.