Commissioned into service in the Italian Regia Marina (Royal Navy) in 1916, she served in World War I, playing an active role in the Adriatic campaign.

On 3 May 1916 Giuseppe Missori, under the command of Capitano di corvetta (Corvette Captain) Ferrero, got underway with her sister ship Francesco Nullo and the scout cruisers Cesare Rossarol and Guglielmo Pepe to provide distant support to the destroyers Fuciliere and Zeffiro as they laid a minefield[2] in the Adriatic Sea off Šibenik (known to the Italians as Sebenico) on the coast of Austria-Hungary.

[3] On 12 June 1916, escorted by Cesare Rossarol and Guglielmo Pepe as far as the Austro-Hungarian defensive barrage, Giuseppe Missori and Francesco Nullo supported Fuciliere, Zeffiro, the destroyer Alpino, and the coastal torpedo boats 30 PN and 46 PN as they forced the port of Poreč (known to the Italians as Parenzo) on the western side of Istria, a peninsula on Austria-Hungary's coast, at dawn.

[4] On 1–2 November 1916, Giuseppe Missori, Francesco Nullo, Guglielmo Pepe, and the scout cruiser Alessandro Poerio made ready to provide possible support to an incursion by MAS motor torpedo boats into the Fasana Channel on the southwest coast of Istria.

Giuseppe Missori got underway from Brindisi with the scout cruisers Aquila and Sparviero, the destroyers Antonio Mosto and Indomito, the British light cruisers HMS Gloucester and HMS Newcastle, and the French destroyers Bisson, Commandant Bory, and Commandant Rivière to join other Italian ships in pursuit of the Austro-Hungarians, but after a long chase which also saw some Italian air attacks on the Austro-Hungarian ships, the Austro-Hungarians escaped and all the Italian ships returned to port without damage.

[2] On the Italian side, Francesco Stocco suffered damage which set her on fire[5] and killed and injured some of her crew.

[6] While Giovanni Acerbi remained behind to assist Francesco Stocco, the Austro-Hungarians withdrew toward Pola and the Italians resumed operations in support of their own torpedo boats.

There they disembarked 200 members of the Carabinieri and General Carlo Petitti di Roreto, who proclaimed Italy's annexation of the city to a cheering crowd.

[10][11] Efforts to rescue men trapped aboard the wreck of F14 failed, and they eventually died of asphyxiation by chlorine gas.

[12] On 27–28 June 1940 Giuseppe Missori and Rosolino Pilo transported supplies and 52 soldiers from Taranto, Italy, to Tripoli, Libya.

[14] From 8 to 10 February 1941 Giuseppe Missori, the destroyer Turbine, and the torpedo boats Castore and Orsa escorted the first convoy carrying troops of the German Afrika Korps.

The convoy, composed of the steamers Alicante, Ankara, and Arcturus, had to stop temporarily at Palermo, Sicily, to avoid the British Royal Navy's Force H.[15] Giuseppe Missori began her return voyage to Italy at 08:30 on 11 February 1941, when she and the auxiliary cruiser Deffenu departed Tripoli to escort the steamers Bainsizza, Motia, Sabaudia, and Utilitas to Palermo and Naples.

[15] On 10 April 1941 Giuseppe Missori got underway from Palermo with the torpedo boats Generale Carlo Montanari and Perseo to escort a convoy made up of the steamers Bosforo and Ogaden and the tankers Persiano and Superga to Tripoli.

On 4 June, while the ships were about 20 nautical miles (37 km; 23 mi) from the Kerkennah Islands, they came under attack by British planes which hit Montello and Beatrice Costa.

During the voyage, the Italian crew of Rosolino Pilo overwhelmed the German guards aboard their ship on 26 September, took back control of her, and steamed her to Allied-controlled Brindisi.