Mandelli established her ready-to-wear fashion house, Krizia, in 1954 by bringing suitcases of samples to shops in Milan out of her Fiat 500.

"[1] According to the New York Times, Mandelli was one of the first female fashion designers to create a popular line of men's wear.

[2] Mandelli worked as a teacher for several years until her friend, Flora Dolci, offered use of a flat in Rome for six months rent-free.

[2] In 1964, she unveiled her first black-and-white collection at the Palazzo Pitti in Florence, which earned a Critica della Moda award.

[2] By the end of the 1980s, she bought land in Punta Volpe, Costa Smeralda, and hired the architect Gianni Gamondi to build a luxurious seafront loggia.