Cagnotto, who made her Olympic debut in Sydney in 2000, had always come close. She finished in fourth in both the individual and synchronized three metre springboard events in London four years ago and fifth in the individual event in Beijing.
On Sunday, the 31-year-old took the bronze medal in the women's three metre individual springboard event, adding to a silver she won in the synchronized event last week.
"Now I'm fine and I can retire," she told Reuters after the medal ceremony, during which she stood on the podium and blew kisses to supporters.
"I'm just happy and I'm enjoying this moment because I lost two medals in London by very little points."
In London, she was pipped for bronze in the individual event by Mexico's Laura Sanchez by 0.20 points. In the synchronized, she and Francesca Dallape were 2.7 points behind Canadian duo Jennifer Abel and Emilie Heymans.
Her quest for the bronze medal, however, looked uncertain at certain times on Sunday as she faced strong competition from Abel before she finally came up out on top in her final dive and finished with a 5.55 point advantage.
"I was looking at the scoreboard, I just had one goal and that was to do my best score."
Cagnotto, who is also a police officer, comes from diving stock. Her father, Giorgio, was an Olympic diver who won two silver and two bronze medals over three Games between 1972 and 1980.
Her mother, Carmen Casteiner, was also a national diver.
Now that she's achieved her medal dream, she said she was not tempted to train for another Olympics and that Rio would be her last.
"I'm getting married in September and I will start a new life and we'll see."
(Editing by Greg Stutchbury)
