After becoming officer on September 14, 1906, he served in Libya in 1914 and then took part in the First World War with the rank of captain and later major, earning a silver (for an action in the Carnic Alps in June 1916) and a bronze medal for military valor (for his behaviour during the First Battle of Monte Grappa in December 1917).

In late February the division repelled a Greek offensive aimed at capturing Tepelenë, for which Girotti was awarded a Silver medal for military valor.

[3][4][5] On 15 November of the same year he assumed command of the newly established 6th Alpine Division Alpi Graie, which starting from March 1942 was transferred to Yugoslavia and employed in anti-partisan operations between Danilovgrad (where the divisional headquarters were established) and Podgorica and in the Nikšić area of Montenegro; for his leadership during these operations Girotti was awarded the Knight's Cross of the Military Order of Savoy.

The division was repatriated in January 1943 and redeployed in southern Liguria, with the task of defending the naval base of La Spezia, and on 15 August 1943 Girotti was replaced by General Mario Gorlier and was assigned to the Ministry of War in Rome, where he was at the time of the proclamation of the armistice of Cassibile on 8 September.

He died in Rome on November 3, 1957, and his funeral was attended by Marshal of Italy Giovanni Messe, while a battalion of the 4th Alpini Regiment rendered the military honors during the burial.