The Duca degli Abruzzi-class cruisers were the final version of the and were larger and better protected than their predecessors. The armament was also increased by two extra 152 mm guns, triple turrets replaced twins in the "A" and "Y" positions. The machinery was also revised which led to these ships having a slightly slower maximum speed than their predecessors.
On 9 July at the Battle of Calabria, Giuseppe Garibaldi along with her sister,, fired the first rounds of the engagement. During the engagement, splinters from a 6-inch round fired by Giuseppe Garibaldi hit the British cruiser, damaging her catapult and the reconnaissance aircraft beyond repair. On 1 September, she was part of the fleet that attempted to intercept the Hats convoy and on 29 September, Giuseppe Garibaldi and the rest of the Italian fleet made another ineffectual sortie against Operation MB 5, a successful British attempt to ressuply Malta. On 11 November, Giuseppe Garibaldi was anchored at Taranto when British aircraft attacked the Italian fleet in the harbour.
On 3 January, the cruiser escorted Italian convoy M 43. On 7 March, GiuseppeGaribaldi took part in Operation V 5, escorting a large Axis convoy to Libya along with another Condottieri-class cruiser, the Eugenio di Savoia. On 14 June the ship participated in the successful action against convoy Vigorous, an attempt to resupply Malta by the Royal Navy. After the armistice, she operated in the South Atlantic together with Allied ships against potential German raiders.
After the war she was retained by the Marina Militare and modernized with minor changes of the armament and a radar. She was decommissioned in 1953 and reconstructed as a guided missile cruiser. The new ship was rebuilt in the La Spezia Arsenal starting from 1957, and, at her completion in 1961, she was named flagship of the Italian Navy. The reconstruction included a complete overhauling of the superstructure, while the hull kept its original dimensions. Apart from some minor changes, much of the latter's rebuilding included four launchers for the U.S. designed UGM-27 Polaris nuclear ballistic missiles. The US never provided the missiles. Instead the Italian government set to develop an indigenous missile, called Alfa. The propulsion system remained the same. The rest of the armament was radically altered: a RIM-2 Terriermissile launcher made Giuseppe Garibaldi the first missile cruiser in Europe. The previous artillery was replaced by four 135/45 mm guns in two twin turrets and eight Oto Melara76/62mm Type MMIAA guns. Electronics included several radars and fire control systems. She was decommissioned in 1971 and scrapped the following year.