On the first day of World War II he was arrested by the gestapo together with painter Josef Čapek and others and was subsequently imprisoned in German concentration camps Dachau and Buchenwald. However, he survived, returned home and began to teach at the Vysoká škola uměleckoprůmyslová v Praze (VŠUP—Academy of Arts, Architecture and Design in Prague). Filla's teachings at the Academy ensure the continuance of Czech Cubism, and his influence is notable in the works of his pupil Milos Reindl amongst others.