Designed by the brilliant Zygmund Pulaski, the PZL P.11 was a gull-winged monoplane fighter built at a time when most countries were still devoted to the biplane. Unfortunately, Pulaski was killed in a crash and replaced by W. Jakimiuk yet still the P.11 eventually entered service during the second half of the decade where it was the mainstay of what was one of the largest and most powerful air forces in Europe at the time. Sadly, and despite a number of improvements throughout its service life, the P.11 found itself hopeless outclassed by more modern German fighters like the Bf 109 but that did not stop them from performing a gallant defense after the outbreak of war where 12 squadrons manged to destroy 125 Luftwaffe aircraft at a cost of 114 of their own. Many were exported to Bulgaria and Greece with local production undertaken in Romania.

First flight of the prototype P.11/I powered by Gnome-Rhône enignes took place in August 1931, these were followed by two more prototypes and then the production P.11a, the P.11b (for Romania), and the improved P.11c which featured additional guns, a revised fuselage, raised pilot's seat, and lowered engine which improved visibility. Production was reinstated in 1939 on the verge of the German invasion, new variants were known as the P.11g with more powerful engines. Finally, Romanian aircraft built by IAR were known as the P.11f.