During the early stages of World War I, "Parramatta" operated with the Australian fleet in the search for the German East Asia Squadron, then was involved in the capture of German colonies in the South Pacific region, including German New Guinea, and the consolidation of Allied occupation in these regions. On 5 February 1915, "Parramatta" and sister ships "Yarra" and sailed for Australia, where they were used for convoy escort duties along the continent's eastern coast until November. The ships were refitted at Sydney, then sent to patrol the region around Malaya, the East Indies, and the Philippines. "Parramatta" returned to Australia on 17 July 1916, and patrolled home waters until 17 May 1917, when she and her sister ships were ordered to Malta.