István Rusznyák

István Rusznyák (Budapest, 22 January 1889 - Budapest, 15 October 1974), was a Hungarian physician. He was the President of the Hungarian Academy of Sciences between 1949 and 1970.

Rusznyák came from a family of Jewish intellectuals. In 1911 he got a diploma in medicine from the Budapest University of Medical Sciences. He worked in the Pathology Department. He fought in the First World War. In 1926, private professor lecturers, he worked as a lecturer on.

Between 1931-1945 he was the director of the Department of Medicine i Medical Faculty of University of Szeged. In 1937/38 school year he was elected dean. With start of Second World War In 1944, he was deported to Austria. At the end of the Second World War, he came back in Budapest and worked as the Head of the Department of Internal Medicine. In 1946, he was elected a full member of the Hungarian Academy of Sciences and was elected its president in 1949. In 1963, he retired as a university professor but he continued as the President of the Hungarian Academy of Sciences until 1970. He remained an academic advisor from 1971 until his death in 1974.

Along with Albert Szent-Györgyi he discovered Vitamin P and proved that chemically it belongs to the flavones.