After Italy entered the First World War, he was sent to serve in a staff position in the Julian Alps Front. On 9 November 1915, he was promoted to major. In May 1916, he was appointed chief of staff of the 31st Infantry Division. His participation in the Sixth Battle of the Isonzo with the division earned him his first Silver Medal of Military Valor. In February 1917, he was transferred to the general staff. In May he won his second Silver Medal of Military Valor for his participation in the Tenth Battle of the Isonzo in the Bosco Malo-Pod Horite area and was promoted to lieutenant-colonel on 31 May. As chief of staff of the 65th Infantry Division from July, he fought in the Eleventh Battle of the Isonzo in the Mešnjak area and won his third Silver Medal in the process, and then, he fought in the disastrous Battle of Caporetto. From April 1918 he was chief of staff of the 34th Infantry Division. His organizational ability was recognised in September by a commendation and the award of a knighthood in the Military Order of Savoy. After the armistice, he spent some time in the Tonale–Garda area, moved to the post of commandant in Padua and then joined the Rome garrison and the general staff.