Cagnotto won her first European gold medal at the 2004 championships in Madrid at the age of 19, winning the 10-meter platform event and also receiving a bronze medal for her performance in the 3-meter springboard competition. After a disappointing performance in the 10-meter platform final round at the Montreal 2005 World Championships, she won the bronze medal in the 3-meter springboard event. Cagnotto won a third consecutive bronze medal in the 3-meter springboard at the Rome 2009 World Championships, after a 4th place in the 1-meter springboard event. Together with Francesca Dallapè, she also won a silver medal in the 3-meter springboard synchronized event.