 Stevens enlisted on 2 July 1915 in the Australian Imperial Force in the Signal Corp and sailed for Egypt in November with the rank of corporal.He was promoted in March 1916 to sergeant and served with the 4th Divisional Signal Company.In June, he was sent to France and was awarded the Meritorious Service Medal for "devotion and keen sense of duty" during the battles of Pozières and the Ypres salient.