Before fleeing Nazi Germany, Wischnitzer was curator of the Jewish Museum Berlin, art editor of the Yiddish magazines Rimon and Milgroym (both 1922-1924), and art and architecture editor of the Encyclopaedia Judaica. She was one of the most important Jewish art critics of the century. Wischnitzer immigrated to the United States in 1940. She was made a fellow of the American Academy for Jewish Research. She was a professor at Stern College for Women of Yeshiva University from 1956 until she retired in 1968.