The Diary of Anne Frank is based on the real-life book written by a young Jewish girl who spent two years with her family hiding from the Nazis. Anne (Millie Perkins), her sister Margot (Diane Baker), and her parents Otto (Joseph Schildkraut) and Edith (Gusti Huber) are being sheltered by friends in Amsterdam. Along with another family and a single man Albert Dussell (Ed Wynn), they are secreted in a hidden attic above a factory, and are supplied with food by kind and loyal friends. In such close quarters, Anne and the others struggle to get along with each other, keep their spirits up, and remain discreet and quiet so that their hiding place remains secure.