Schroth began her career as a child actress, and made her film debut at the age of nine in 1931's Max Ophüls' comedy Dann schon lieber Lebertran opposite her mother.

Her early film successes include Spiel im Sommerwind (1938), Weisser Flieder (1939) and Kitty and the World Conference (1939), the latter of which was her first leading role.

After the war, she continued her work extensively in film and returned to the theatre, with engagements in Vienna, Düsseldorf, Hamburg, Berlin and Munich.

These include Jane Wyman's character of Carolina Hill in Just for You (1952), Shirley MacLaine in Irma La Douce (1963), Elizabeth Taylor's role as Martha in Who's Afraid of Virginia Woolf?

In 1944, Schroth had a short-term marriage with German stage and film actor Carl Raddatz; the union ended in divorce.