From 1939 to 1941, Aickin worked as an associate to High Court Justice (later
Chief Justice)
Owen Dixon. From 1942 to 1944, Aickin served as part of the Australian
legation to Washington, D.C. (predecessor of the
Embassy of Australia in Washington). In 1948, he joined the legal department of the
United Nations in New York City, becoming a legal adviser. On returning to Australia, Aickin lectured at the University of Melbourne, before being admitted to the
Victorian Bar in 1949. He became one of Victoria's most prominent barristers, and in 1957 was made a
Queen's Counsel. He was elected to the inaugural council of
La Trobe University in 1966, and was also appointed to a number of company boards, including those of
Mayne Nickless (1958),
P&O Australia (1969),
Comalco (1970), and
BHP (1971). He resigned his directorships upon his appointment to the High Court in 1976. ==High Court==