During Goulart's first ever fashion show appearance, she experienced a wardrobe malfunction when her top fell open. The unfortunate incident made many Brazilian newspapers and remains her most embarrassing moment. She was able to put her rocky start behind her and returned to the runway to model collections for A-list designers such as Bill Blass, Balenciaga, Bottega Veneta, Oscar de la Renta, Valentino, Jil Sander, Chanel, Michael Kors, Ralph Lauren and Stella McCartney, among many others. Goulart has also modeled for H&M, Express, Neiman Marcus, Missoni and Dsquared.
She first appeared in the Victoria's Secret Fashion Show in 2005, the year she was contracted as an Angel. Although she is no longer an Angel, Goulart walked in the 2008, 2009 and 2010 Victoria's Secret Fashion Shows. She has shot for top photographers such as Terry Richardson, David Sims, Greg Kadel, and Vincent Peters for such publications as French and Japanese Vogue, French magazine, and Numero. Goulart can be seen in the fall 2009 H&M campaign.
In 2011, Goulart appeared in the Sports Illustrated Swimsuit Issue. The same year, she ranked number 100 in FHM magazine's list of the 100 Sexiest Women In The World.