Commissioned into service in the Italian Regia Marina (Royal Navy) in 1915, she served in World War I, playing an active role in the Adriatic campaign and seeing action in the Battle of the Strait of Otranto in 1917.

[2][3] On 29 December 1915 Rosolino Pilo to join various formations of Allied warships in pursuing an Austro-Hungarian force composed of the scout cruiser Helgoland and the destroyers Balaton, Csepel, Lika, Tátra, and Triglav, which had bombarded the harbor at Durrës (known to the Italians as Durazzo) on the coast of the Principality of Albania, sinking the Greek steamer Mikael and two sailing ships while losing Lika, which struck a mine.

[4] On 23 February 1916, Rosolino Pilo, the British light cruiser HMS Liverpool, and the French destroyer Casque provided distant cover to a convoy of 12 steamers and two tugs in transit from Italy to Durrës.

[4] On the night of 14–15 May 1917, the Battle of the Strait of Otranto, the largest naval action of the Adriatic Campaign of World War I, began when the Austro-Hungarian Navy staged a two-pronged attack against the Otranto Barrage aimed both at destroying naval drifters — armed fishing boats that patrolled the anti-submarine barrier the barrage formed — and, as a diversionary action, at destroying an Italian convoy bound from Greece to Albania.

At 04:50 on 15 May, following news of these attacks, Rosolino Pilo, the Italian destroyer Simone Schiaffino, and the British light cruiser HMS Dartmouth made ready for sea to intervene in the clash.

Dartmouth, the British light cruiser HMS Bristol, Antonio Mosto, and the Italian destroyer Giovanni Acerbi placed themselves between Aquila and the Austro-Hungarian ships and opened fire on them at 09:30 at a range of 8,500 metres (9,300 yd).

All the major warships suffered damage during the battle, but Rosolino Pilo′s formation had to discontinue the action and withdraw at 12:05 when it neared Cattaro, from which the Austro-Hungarian armored cruiser Sankt Georg and destroyers Tátra and Warasdiner had sortied to intervene in the engagement.

[4] An Austro-Hungarian Navy force consisting of Helgoland and the destroyers Balaton, Csepel, Lika, Orjen, Tátra, and Triglav left Cattaro on 18 October 1917 to attack Italian convoys.

At 06:30 on 19 October 1917, the destroyer Insidioso, the scout cruisers Alessandro Poerio and Guglielmo Pepe, and the destroyers Pilade Bronzetti and Simone Schiaffino got underway from Brindisi to pursue the Austro-Hungarians, and Rosolino Pilo, Ippolito Nievo, and the British light cruiser HMS Weymouth diverted from a voyage from Vlorë (known to the Italians as Valona), Albania, to Brindisi to join the pursuit.

With the light cruisers Giovanni dalle Bande Nere and Bartolomeo Colleoni and the destroyers Grecale, Libeccio, Maestrale, and Scirocco in distant support,[9][10] the convoy arrived safely at Benghazi, Libya, on 8 July.

[11] On 22 May 1942, Rosolino Pilo and the destroyer Francesco Crispi were escorting a convoy composed of the steamers Balcan and Chisone when the Italians sighted an incoming torpedo.

At the time, Rosolino Pilo, under the command of Tenente di vascello (Ship-of-the-Line Lieutenant) Giuseppe Tullio Faggioni, was at Durrës on the coast of the Italian Protectorate of Albania.

[7][13] At 18:30 on 8 September her chief radio operator received the announcement of the armistice and informed the ship's executive officer, Sottotenente di vascello (Ship-of-the-Line Sublieutenant) Giovanni Buizza.

They implemented the plan at midnight on 25–26 September 1943: After pretending to have sighted a submarine and sounding a siren to distract the German guards, a large number of Italians rushed onto Rosolino Pilo′s deck.

Rosolino Pilo initially set course for Cape Linguetta on the Karaburun Peninsula on the coast of Albania in order to evade German forces searching for her, then headed for Brindisi, where she arrived on 26 September 1943.