After retiring as a player in 1926, Weisz became an assistant coach at Alessandria before moving to Internazionale, where he won one championship in the 1929/1930 season. Weisz had three separate spells as manager of Inter, 1926-1928, 1929-1931, and 1932-1934, managing Giuseppe Meazza among his players. He also coached Bari, Novara and Bologna, where he won two league titles before he was forced to flee Italy with his wife and two children following the enactment of the Italian Racial Laws. Weisz finished his career by coaching DFC in the Netherlands, leaving in 1940 following the outbreak of the Second World War. He died four years later at Auschwitz, gassed immediately with his family upon entering Birkenau.