In September 1940, 20° Gruppo (Squadriglie 351/352/353), commanded by Maggiore Mario Bonzano, equipped with Fiat G.50 was part of the 56° Stormo formed to operate during the Battle of Britain as part of the Corpo Aereo Italiano based in Belgium, with 18° Gruppo (Fiat CR.42). Their use was hampered by their slow speed, open cockpits and short range. At the beginning of 1941, the C.A.I. came back to Italy, except for two G.50 Squadriglie that stayed in Belgium with Luftflotte 2, until April. While with the C.A.I. the Fiats flew 429 missioni-velivoli (missions), 34 escorts and 26 scrambles but could not manage to engage enemy aircraft. One aircraft was lost and seven more were damaged. While with Luftflotte 2, 20° Gruppo lost four additional fighters and two pilots were killed (Roncali (13 February 1941) and Meneghini (3 April), both of 352a Squadriglia), while two G.50s were damaged by German fighters and flak. The experiences of the early series G.50s over Britain showed the inadequacies of the type. Its operations were almost useless in the campaign because they were too short-ranged and stationed too away from England. The G.50s had limited endurance, with missions rarely exceeding one hour. The G.50bis with larger fuel tanks was already in production, but it was not sent to 20° Gruppo in time. Performance was also lacking; when 22 Fiat G.50s intercepted several Hawker Hurricanes on 5 November 1940, the RAF fighters easily escaped. On 21 November, when a Bristol Blenheim attacked the Medgelem airfield two G.50s scrambled, but lost the bomber in the clouds. On 23 November, G.50s followed four Hurricanes, but were unable to close on them. Another fruitless intercept took place on 31 January, when G.50s lost a Blenheim that escaped into the clouds. The last sighting of enemy aircraft (fighters) occurred on 8 April 1941, when, once again, the elusive targets were not intercepted.
The G.50s were early models with an open canopy, useful in Mediterranean climes, but the pilots suffered heavily in the bad weather of northern Europe. The aircraft was also under-equipped, with a mediocre radio set (powered by batteries, prone to freeze at altitude) and lacking any armour protection. In Belgium, 20° Gruppo had the opportunity to see the Bf 109 in action with several G.50 pilots trained to fly the type with two Bf 109Es sent to the Gruppo in mid-January 1941. The G.50s returned to Italy and later the 20° Gruppo had the G.50bis that had the endurance required for operational missions utilizing an extra fuel tank in the internal fuselage section originally configured as a bomb bay, but this series was primarily utilized over Africa. In the second half of the war, the G.50 operated as a multirole fighter/ground attack aircraft, with external bombs only. During the opening phase of the Allied invasion of Sicily, the G.50 was the most numerous aircraft used by the Regia Aeronautica to counter attack the Allied landings. Just before the invasion, the Regia Aeronautica moved to Southern Italy. 50° Stormo Assalto, a specialized ground attack unit was equipped with Fiat G.50bis fighter-bombers. As soon the invasion started, on 10 July 1943, further units were rushed to the area. With other Italian and German ground attack units, 45 Fiat G.50bis of 158° and 159° Gruppi Assalto, from Pistoia were committed to attack ships, landing craft and troops. On 11 July, 10 of them were in action with Re.2002s (escorted by five Re.2005s of 362a Squadriglia), when they were intercepted by an overwhelming fighter "umbrella". Three G.50s were shot down, including Tenente Colonnello Guido Nobili, commander of 5° Stormo Assalto. The remainder landed on an airfield but were destroyed by an incoming air attack. By the time of the Italian Armistice with the Allies, only a few G.50s were left in Italian service. Some were used as part of the Italian Co-Belligerent Air Force, while four others were used by the Aeronautica Nazionale Repubblicana as fighter trainers. The top scoring Italian pilot in a Fiat G.50 was Furio Lauri, who was credited with 11 "kills" before the end of 1941 with a final score of 18.
The first 27 Fiat G.50s, belonging to Squadriglie 150a and 152a from 2° Gruppo Autonomo C.T., arrived in Libya on 27 December 1940, operating from Brindisi and Grottaglie airfields. They flew their first combat mission on 9 January 1941 when Capitano Pilota Tullio Del Prato (already known to have been a Reggiane Test pilot), Comandante of 150a Squadriglia encountered a Hawker Hurricane Mk I on the front line that attacked him, forcing the Fiat to crash-land in the desert.[25] On 25 January 1941, a new unit, 20° Gruppo Autonomo C.T., with 351a, 360a and 378a Squadriglie, commanded by Maggiore pilota Pietro Bianchi, arrived in Libya, with 31 brand new Fiat monoplanes. On 27 May, 20° Gruppo was reinforced by 151a Squadriglia, equipped with the new Fiat G.50bis version. Caught up in the chaotic retreat of Italian army in the winter of 1940–41, the Fiat G.50s saw little action.
In Africa, although the G.50s were mainly outperformed, G.50 pilots sometimes managed to shoot down the faster and better armed Hurricanes and P-40s. G.50s were faster than biplanes, as showed in 1939 air exercises, so they could be useful against British bombers, even if their armament was relatively weak and often insufficient to shot down their target. By that time, the G.50s in North Africa were the better -bis version which, although heavier,had almost two hours of flight time as a result of the extra fuel carried. The G.50s did not carry bombs, but used HE and incendiary bullets. Their usual tactic with the G.50 was to dive from 1,500 meters but the type never flew very high over Africa, with the usual ceiling not exceeding 4,500 m. The aircraft were still lacking radios and the desert sand, despite their air filter, could cut the engine lifespan to only 70–80 hours. In the hands of expert pilots, the Fiat G.50 could score multiple kills in a single action. On the evening of 9 July 1941, Sergente Maggiore Aldo Buvoli of 378a Squadriglia, 155° Gruppo Autonomo, took off from Castel Benito airfield to patrol Tripoli harbour, and duly intercepted seven Blenheim light bombers that were performing a low-level attack on the ships. The Blenheims were already being pursued by two Fiat CR.42 biplanes from 151° Gruppo when Buvoli attacked the bombers shooting at each of them, in sequence. One Blenheim ditched in the sea while another was shot down a few miles north of Tripoli. Two more Blenheims never returned to Luqa airfield in Malta and were posted as missing. For these successes Buvoli was awarded with the Medaglia d'argento al Valor Militare and was subsequently credited with four kills, No. 110 Squadron RAF reported the loss of a similar number of Blenheims IVs on its very first mission since arriving in Malta from UK in early July.
One of the units fielded by the Regia Aeronautica was the 155° Gruppo, based at Derna airfield. One of the few first claims by "Freccias" pilots was on 9 April 1941, when Tenente Pilota Carlo Cugnasca (an expert pilot, and the first one to deliver a G.50 to Finland), attacked three Hurricanes Mk Is from No. 73 Squadron RAF, claiming one although this air victory was not confirmed.[29] On his return, he was forced to crash-land his G.50, flipping over on the airstrip, but remaining unharmed. At low level, the clashes were often confused and with unpredictable effects. Tactical surprise was often what made the difference, as the next battle showed. Cugnasca was still in action on 14 April when 66 Axis aircraft attacked Tobruk. They were mainly Ju.87 Stukas (42 from Lutftwaffe III./StG 1 and II./StG 2, and seven from 96° Gruppo), escorted by eight G.50s (155° Gr), four C.R.42s (18° Gr) and five Bf 110 (III.ZG 26). The defenders of 73 Sqn RAF were outnumbered. RAF Hurricanes had to ignore the Axis fighters and concentrate on attacking the bombers as the Stukas were the greatest threat, being such precise and lethal machines. Cugnasca and Marinelli attacked H.G. Webster, when he was shooting at a Stuka. Hurricanes with Stokes air-filter were only marginally faster than a G.50, so Webster was followed and finally shot down and killed (Hurricane V7553) over Tobruk. "Smudgeon" Smith, a Canadian ace (with five victories) saw what was going on, and attacked both Cugnasca and Marinelli, shooting down and killing them. Finally, Smith attacked and damaged another G.50, but commander Fanello saw him and saved the third G.50, surprising and shooting down Smith. That day was a draw, with two G.50s and two Hurricane lost. Both Smith and Cugnasca were well known and respected, so it was also a heavy human loss for both sides.
G.50s operated from Martuba airfield with the first attack over Sidi el Barrani airfield made seven days later. On 4 July 1941, six G.50s attacked again, strafing aircraft and ground equipment. The worst day for the G50s was during 'Operation Crusader'. On 18 November, the Desert Air Force destroyed 13 aircraft on the Ain el Gazala airfields; 10 of them were G.50s. On 19 November, 20° Gruppo based at Sid el Rezegh suffered heavy losses when British armoured forces (40 Crusaders of 6th RTR and several units of 3rd Brigade, South African Regiment, both part of 7th Armoured Brigade) suddenly attacked the airfield. Of the 19 G.50s, only three escaped whilst 80 pilots and ground crew were taken POW. In only two days, Regia Aeronautica lost 34 aircraft. In total, G.50s losses were no less than 26, and the 20° Gruppo was almost destroyed, since it had only 36 G.50s with 27 of them serviceable.