Dunstan lost a leg while with the A.I.F. in Tobruk. In 1942 he was discharged from the A.I.F. and joined the R.A.A.F. serving a tour in Europe. After the war he worked as a journalist and then film critic for the Melbourne Herald. In 1953 he travelled to Italy to meet the artilleryman whom he believed had fired the shell that wounded him at Tobruk, and four years later sponsored the man's son as a migrant to Australia. In 1956 Dunstan was elected to the Victorian parliament as the Liberal member for Mornington. He went on to serve as a cabinet secretary, Minister of Water Supply and, later, Minister of Public Works.