In 1996, she made it to the finals of the Elite Model Look Contest when she was just 13. She moved from Brazil to Milan in 1997 to start her modelling career. In 1999, at the age of 16, she appeared in the Victoria's Secret lingerie catalogue. This created a huge controversy as Victoria's Secret had earlier stated that its policy was not to sign models younger than 21 years. However, the publicity generated by this controversy proved beneficial to Isabeli and she quickly rose to fame. Following the Victoria's Secret shoot, she was signed by the likes of Versace, Ralph Lauren and Valentino. She has modelled for Sports Illustrated Swimsuit Issue, Marie Claire, ELLE and Vogue. She is currently living in Brazil with her new husband, TV actor and model Henri Castelli, after she separated from her former husband Alvaro Jacomossi, who is also a model. She has a son called Zion from her marriage with Alvaro Jacomossi. She is currently pregnant with her second child which is believed to be a girl.