Kraus family moved to Croatia from Moravia and Czech Republic during Austro-Hungarian Empire.
Kraus grandmother Ruža was born in Bjelovar where she lived with her parents, Samuel and Nanete (née Löwy) Schwarz.
During World War II his father and grandmother escaped the Nazi and Ustaše persecutions through Rijeka from where they went to Italy.
When he returned to Zagreb, he got a job at the Sisters of Charity Hospital where he serves as the head of the urology department.
[3] Kraus became the president of the Jewish community of Zagreb in 1993 after Nenad Porges withdrew from the position.