After the beginning of the First World War in 1914 until 1917, "Parramatta" was conducted patrols in the Pacific and South-East Asia, before she and her sister ships were transferred to the Mediterranean for anti-submarine operations. She returned to Australia in 1919 and was placed in reserve. Apart from a brief period of full commission during the visit of the Prince of Wales in 1920, "Parramatta" remained in reserve until 1928. She was fully decommissioned in 1928, stripped of parts, and sold for use as prisoner accommodation on the Hawkesbury River. After changing hands several times, the hull ran aground during a gale in 1933, and was left to rust. In 1973, the bow and stern sections were salvaged, and converted into memorials.