Paula, nicknamed "La Peque" (The small one) was born in San Fernando, Argentina. She lives with her parents in Tigre, close to the capital city. She began swimming at the age of four and a year later she partook in gymnastics. Her inspiration to begin judo arose when she was 9, and her younger brother Marco came home from school beaten up. Her father Aldo used to practice judo when he was young so he decided to send Marco in a judo club. Paula was curious and wanted to go too.
Her first judo club was Club San Fernando. She very soon won her first tournament and when she decided to continue practising judo she moved to bigger Club Estudiantes de La Plata. First years she competed in the -44 kg division but later moved up to the - 48 kg category.
She is a big football fan and also plays football with her friends. She had a time period in her life when she wanted to play football professionally but she left the idea thereafter to pursue her judo career. Her favorite club is Boca Juniors and her home club Estudiantes de La Plata.
During the 2008 Summer Olympic Games in Beijing in an interview said that she is single and her mother Mirta commented that it was like "You are engaged to judo".
Paula has a younger brother called Marco who is supporting her on her journeys around world tournaments and an older sister called Estefanía who is a psychologist.
She studied medicine at the University of Buenos Aires and graduated in March 2014.
In December 2015, Paula received the Gold Olimpia Award as the best athlete of the year from her country.
She was the flag bearer for her country at the closing ceremony of the 2016 Summer Olympic Games held in Rio de Janeiro, Brazil.
She won the bronze medal at 2008 Summer Olympic Games in one of the most dramatic matches of whole tournament. She stood against Pak Ok-Song from North Korea. The Korean judoka was active whole match and got a koka in middle of the match for activity. Drama came in last 10 seconds when Pak began a technique but Paula made use of it for her technique, which was a counter to the Korean's move. Problems arose when the jury counted the technique for Pak, perhaps because she began to move first. In the end Pak celebrated the medal and Paula cried but her trainer Carlos Denegri lodged an objection so the jury checked the video. Finally they agreed that it was Pareto who made the technique (Kuchiki-taoshi) and so she took the medal.
She is also very successful on continental games and championships like Pan American Games.
In August 2015, Paula won the gold medal at the World Judo Championship in Astana, Kazakhstan, her first title at a World Championship.
At the 2016 Summer Olympic Games, Paula defeated Jeong Bo-kyeong to capture her first Olympic gold medal.