Else-Mitchell was called to the New South Wales Bar on 16 February 1939 and to the Victorian Bar in 1954. In 1941/42 he was the Assistant Honorary Secretary to the Council of the
New South Wales Bar Association. He relinquished his practice during World War II to become Secretary of the Commonwealth Rationing Commission from 1943 to 1945. He returned to practice in 1945, specialising in constitutional law, commercial law and equity. He was counsel for the Commonwealth and New South Wales governments in a number of Privy Council appeals from 1950 to 1956. He was editor of the
Australian Law Journal from 1946 to 1958 and a lecturer in Constitutional Law at the University of Sydney from 1951 to 1958. He was made a Queen's Counsel in 1955. Else-Mitchell was appointed a Judge of the
New South Wales Supreme Court on 8 September 1958. He served in the
Land and Valuation Court from 1962, initially as an additional Judge from 1 January 1962, as a Deputy Judge on six occasions from 15 March 1965 to 16 August 1972, and finally as a Judge of the Court from 31 July 1972. He retired from both Courts on 1 October 1974. Else-Mitchell was Chairman of the New South Wales Royal Commission of inquiry into rating, valuation and Local Government finance from 28 August 1965 to 2 May 1967 and Chairman of the Commonwealth Commission of inquiry into land tenures from 4 May 1973 to 6 February 1976. On 1 October 1974 he took up the position of Chairman of the Commonwealth Grants Commission and moved to Canberra. He held this position until 30 June 1989. He was also Chairman of the
Legal Aid Commission ACT from 1977 to 1980 and the Commonwealth Legal Aid Council from 6 February 1980 to 1984, as well as the Committee of Inquiry into Assets and Public Debt, ACT (1989), the National Local Approvals Committee (1989-1992), and the Casino Surveillance Authority ACT (1990-2000). The community organisations in which he was involved included the National Trust of Australia, the
Royal Australian Historical Society, the Historic Buildings and Sites Committee (NSW), the Federation of Australian Historical Societies, the Captain Cook Bi-centenary Arts and Historical Committee, the Australian Bicentennial Authority, the
Arts Council of Australia (NSW Division), the Public Library of NSW, the Library Board of NSW, the Library Council of NSW, the
National Library of Australia, the ACT and Canberra Public Library Service, the Archives Authority of NSW, the Medico Legal Society NSW, St Vincent's Hospital Board, the NSW Association for Mental Health, Macquarie University, Canberra College of Advanced Education, the Royal Australian Institute of Public Administration (NSW), the Centre for Research on Federal Financial Relations at the Australian National University, the Australian Institute of Urban Studies, and the Royal Australian Planning Institute. Else-Mitchell was the author of 'Hire Purchase Law' (1941, 1955, 1961, 1968), and contributor and/or editor to 'Property Legislation and War Damage' (1942), 'Land Tax Law' (1957), 'Essays on the Australian Constitution' (1952, 1961), 'Public Administration in Australia' (1958, 1968, 1973), and 'Canberra; a people's capital?' (1988). He wrote numerous articles on Australian history, law, public administration, planning, public finance and land valuation. ==Later life and legacy==