In the years prior to World War I, May Tilton trained as a nurse at Launceston, in Tasmania. During World War I, she enlisted and served with the Australian Army Nursing Service in Egypt, England, France, Belgium and South Africa. Following World War I, she returned to nursing in Melbourne, where she was active within returned service circles. During World War I her brother Jack also served in the AIF, and spent part of the war as a prisoner of war in Germany.