He was professor of haematology and director of the Institute for Leukaemia at the University of Paris.
After graduating in medicine in Paris in 1926 he commenced his laboratory training with the bacteriologist Gaston Ramon at the Pasteur Institute in 1929.
In 1932 Bernard gave the first description of the use of high dosage radiotherapy in the treatment of Hodgkin's disease.
Bernard's research has ranged from the demonstration of neoplastic nature of leukaemia (1933–1937) to the formulation of methods of treatment.
[1] During the German occupation of France, Bernard was active in the French Resistance.