During World War II the regiment was assigned to the 12th Infantry Division "Sassari", which in 1941 participated in the invasion of Yugoslavia.

[2] On 1 March 1915 the 151st Infantry Regiment (Brigade "Sassari") was formed in Sinnai near Cagliari in the South of Sardinia.

By 18 June the positions were back in Italian hands, but the brigade had suffered 3,120 casualties, more than half of the personnel it had entered the front with.

[2][8] On 3 August 1916 King Victor Emmanuel III awarded to the regiments of the Brigade "Sassari" Italy's highest military honor, the Gold Medal of Military Valor, for having retaken the lost Italian positions on the Sette Comuni plateau.

After the Italian defeat in the Battle of Caporetto the brigade fought delaying actions at Buttrio and on the Monticano river from 27 October to 8 November.

[1][2][8] On 15 June 1920 the King awarded the regiments of the Brigade "Sassari" for having retaken Col del Rosso and Col d'Echelle with a second Gold Medal of Military Valor, making the two regiments the only units to be twice awarded a Gold Medal during the entire war.

[1][2][7][5][11][12] At the outbreak of World War II the regiment consisted of a command, a command company, three fusilier battalions, a support weapons battery equipped with 65/17 infantry support guns, and a mortar company equipped with 81mm Mod.

In March 1943, after the Battle of the Neretva, the division was transferred to Rome to defend the city in case of an allied attack.

[5][1][2] After the announcement of the Armistice of Cassibile on 8 September 1943 the division was tasked with defending Rome from Italy's former German allies.

Soon after the Italian military units surrendered to the Germans as the flight of the King Victor Emmanuel III from Rome made further resistance senseless.

Before surrendering the Italian soldiers handed their weapons over to the civilian population, which was quick to form an organized resistance movement in the city.

On 1 September 1962 regiment entered the newly raised Trieste Military Command, which was tasked with the defence of the city.

The Maneuver Support Company is equipped with 120mm mortars and Spike MR anti-tank guided missiles.