In June 1944, the Italian Co-Belligerent Air Force (ICAF) received 170 P-39s, most of them -Qs, and a few -Ns (15th USAAF surplus aircraft stored in Napoli-Capodichino airfield) and also at least one -L and five -Ms.
The P-39 N (without the underwing fairings for 12.7 mm machine guns) had engines with about 200 hours; a little newer than the P-39Q engines with 30–150 hours.
A total of 149 P-39s would be used: the P-39N for training, while newer Qs were used in the front line.

In June–July 1944, Gruppi 12°, 9° and 10° of 4° Stormo, moved to Campo Vesuvio airstrip to re-equip with the P-39s.
The site was not suitable and, in three months of training, 11 accidents occurred, due to engine failures and poor maintenance of the base.
Three pilots died and two were seriously injured.
One of the victims, on 25 August 1944, was the "ace of aces", Sergente Maggiore Teresio Vittorio Martinoli.

The three groups of 4° Stormo were first sent to Leverano (Lecce) airstrip, then in mid-October, to Galatina airfield.
At the end of the training, eight more accidents occurred.
 Almost 70 aircraft were operational, and on 18 September 1944, 12° Group's P-39s flew their first mission over Albania.
Concentrating on ground attack, the Italian P-39s proved to be suitable in this role, losing 10 aircraft  between 4 November and 3 December 1944, to German flak.

In February–March 1945, 10° and 9° Gruppi moved North of Galatina, in Canne airbase, near Campobasso, while Allied allowed Italian pilots to use the airstrip of Lissa island, in the Adriatic sea, as an intermediate scale during the long sorties on the Balkans.
The 4° Stormo pilots flew many effective ground attack missions on northern Yugoslavia, losing only one more P-39, for engine failure in Sarajevo area, on 2 April 1945.
 The Italian P-39 flew over 3,000 hours of combat.

By the end of the war, 89 P-39s were still at the Canne airport and 13 at the Scuola Addestramento Bombardamento e Caccia ("Training School for Bombers and Fighters") at Frosinone airfield.
In 10 months of operational service, the 4° Stormo  had been awarded three Medaglia d'Oro al Valore Militare "alla memoria".
After the war the P-39s were taken over by the Aeronautica Militare Italiana (the new Italian air force) and used for several years as training aircraft.
In Galatina fighter training unit  (Scuola Caccia), war veteran Tenente colonnello Francis Leoncini was killed during a flying accident, on 10 May 1950.
In June 1944, the Italian Co-Belligerent Air Force (ICAF) received 170 P-39s, most of them -Qs, and a few -Ns (15th USAAF surplus aircraft stored in Napoli-Capodichino airfield) and also at least one -L and five -Ms. The P-39 N (without the underwing fairings for 12.7 mm machine guns) had engines with about 200 hours; a little newer than the P-39Q engines with 30–150 hours. A total of 149 P-39s would be used: the P-39N for training, while newer Qs were used in the front line.
In June–July 1944, Gruppi 12°, 9° and 10° of 4° Stormo, moved to Campo Vesuvio airstrip to re-equip with the P-39s. The site was not suitable and, in three months of training, 11 accidents occurred, due to engine failures and poor maintenance of the base. Three pilots died and two were seriously injured. One of the victims, on 25 August 1944, was the "ace of aces", Sergente Maggiore Teresio Vittorio Martinoli.
The three groups of 4° Stormo were first sent to Leverano (Lecce) airstrip, then in mid-October, to Galatina airfield. At the end of the training, eight more accidents occurred.  Almost 70 aircraft were operational, and on 18 September 1944, 12° Group's P-39s flew their first mission over Albania. Concentrating on ground attack, the Italian P-39s proved to be suitable in this role, losing 10 aircraft  between 4 November and 3 December 1944, to German flak. 
In February–March 1945, 10° and 9° Gruppi moved North of Galatina, in Canne airbase, near Campobasso, while Allied allowed Italian pilots to use the airstrip of Lissa island, in the Adriatic sea, as an intermediate scale during the long sorties on the Balkans. The 4° Stormo pilots flew many effective ground attack missions on northern Yugoslavia, losing only one more P-39, for engine failure in Sarajevo area, on 2 April 1945.  The Italian P-39 flew over 3,000 hours of combat.
By the end of the war, 89 P-39s were still at the Canne airport and 13 at the Scuola Addestramento Bombardamento e Caccia ("Training School for Bombers and Fighters") at Frosinone airfield. In 10 months of operational service, the 4° Stormo  had been awarded three Medaglia d'Oro al Valore Militare "alla memoria". After the war the P-39s were taken over by the Aeronautica Militare Italiana (the new Italian air force) and used for several years as training aircraft. In Galatina fighter training unit  (Scuola Caccia), war veteran Tenente colonnello Francis Leoncini was killed during a flying accident, on 10 May 1950.
Bell P-39 Airacobra