Ken Hetzel was born near Tanunda in South Australia. His grandfather, Carl Hetzel, migrated to Adelaide from Silesia, and his father, Frederick, had a dairy and cheese factory. He was educated at the Gawler High School and subsequently at Prince Alfred College, where he was a prefect in his final year. He had a brilliant career at the Adelaide Medical School, graduating top of his year in 1920. His initiative and ability earned him a research assistantship with TR Elliott and CR (later Sir Charles) Harington in London in 1922. Regrettably illness prevented his from subsequently accepting a Beit fellowship to continue research in London so he returned to Adelaide to enter general practice and to work as an assistant physician to the Adelaide Children's Hospital.

In 1933 he obtained a Rockefeller travelling fellowship and worked in the Thorndike Laboratory, Boston with the then leading world figures Minot and Castle and he was awarded a research fellowship in medicine at the Harvard Medical School. Again however his hopes of an academic career were frustrated, this time by the world depression. He was a Foundation Fellow of the Australasian College having obtained his London College of Physicians membership while at the University College in London in 1923.

Back in Adelaide he rapidly established himself as a leader in medicine. He was director of medical studies from 1947 to 1952 and subsequently dean of the medical faculty of the University of Adelaide from 1952 to 1959 where he presided over the unprecedented expansion of that faculty and the appointment of its first four clinical professors. He was also a member of the University Council for fifteen years from 1954 to 1969. He was responsible for securing approximately $700,000 in donations to the university from several benefactors and had the pleasure of seeing his elder son Basil appointed to the inaugural Michell chair of medicine at Queen Elizabeth Hospital.

In 1945 he travelled through China for twelve months for UNRRA as travelling professor of medicine. He was an honorary assistant physician and then honorary physician at the Royal Adelaide Hospital for a period of twenty-two years from 1935 to 1957. I had the pleasure of being both a student and house physician (intern) on his unit. He was an excellent teacher with a clear methodical mind but it took some time before I, as a student, could cope with those three hour bedside rounds without aching legs and feet. The rounds commenced at 9.15 am sharp and his punctuality and invariable attendance was in marked contrast to some of his peers at the time. He was charming to, and thoughtful for, his interns and without a registrar to help me, as his intern I can vividly remember him willingly coming in to see sick patients for me in the middle of the night. Although he retired compulsorily at the age of sixty from his honorary post at the Royal Adelaide Hospital, his energy and interest in medicine carried him on in active community medical service up to the age of eighty.

In 1922 he married Elenor Watt, they had two sons both of whom have become distinguished Australian physicians themselves. Basil the elder of the two, after a period as Michell professor of medicine at the QEH, became professor of community medicine at Monash and later chief of human nutrition at the CSIRO in Adelaide. Basil himself has been an elder statesmen in medicine and a part time commissioner in the SA Health Commission. Ken Hetzel's other son, Peter, has distinguished himself in cardiology both as a clinician and for many years as head of the Cardio Pulmonary Research Laboratory at the RAH.