She first acted in "Alice, Sweet Alice", a 1976 slasher film. Her next film was "Pretty Baby". In it she played a child prostitute called Violet. She was 12 when it was released and was naked in the film. Some people said this was child pornography and Shields got a lot of attention from this. In February 1980 she was the youngest model ever to be on the cover of Vogue (magazine). She was 14. Later that year she was in adverts for Calvin Klein jeans. In 1981, she starred in The Blue Lagoon.