In 1987, they celebrated their first successes as they undercut the world records in the 400m, 800m and 1500m freestyle. At the Olympic Games a year later in Seoul, she won three gold medals. It was about 400 m and 800 m freestyle as well as the 400 m Individual Medley Olympic champion. In these games, it has provided 400 m freestyle at a world record, which had 2006 stock until May; her world record in the 1500m freestyle event lasted until June 2007., this world record over 800 m freestyle was only at the 2008 Olympic Games in Beijing by Rebecca Adlington improved. At the Olympic Games in Barcelona in 1992, she was Olympic champion over 800 m freestyle and also won silver in the 400m freestyle. At the World Championships, she won the title in 1991 and 1994 over 800 m freestyle. In the years 1987, 1989 and 1990, she was elected Swimmer of the Year.
In 1996, she ended her career. In the domestic Olympic Games in Atlanta could not win any more medals, but they did at the opening ceremony Muhammad Ali the torch with which this lit the Olympic Flame. In the course of her career she had won five Olympic medals and 45 national titles. These are the second most titles in the American Swimming behind Tracy Caulkins. In 2001, she was inducted into the Hall of Fame International Swimming Sports. In 2011, Janet Evans launched her comeback with a view to the 2012 Olympic Games in London.