[9] Nocioni's professional career began in the Argentine basketball league (LNB) in the 1995–96 season, and in 1998–99 he was already named Best Sixth Man.

In 2001, Nocioni went to Vitoria-Gasteiz, where he spent three seasons as a refuerzo (reinforcement player) with Spain's TAU Cerámica of the top-tier level ACB Spanish professional league.

After winning the gold medal at the 2004 Olympics, Nocioni was signed as an undrafted rookie free-agent by the Chicago Bulls.

[10] Nocioni's physical style of defense created controversy around the league, and he was suspended for one game after a hard foul to Detroit Pistons' Tayshaun Prince.

[11] Nocioni had previously committed a hard foul on the Miami Heat's Dwyane Wade and then was shoved past photographers and into the first row of spectators by Udonis Haslem.

A spectator tossed a drink at Nocioni, which was similar to the incident that triggered Pacers–Pistons brawl at The Palace of Auburn Hills.

[12] While giving a teleconference interview with NBA.com, Nocioni spoke about the hard fouls and his suspension, "First, the one with Wade was completely my fault.

I also asked Carlos Delfino to give my apologies to him, so I don't understand why there is a sanction for something totally normal in a game.

[14] In Nocioni's second season with the Chicago Bulls, he averaged 13.0 ppg, 6.1 rpg, and 1.4 apg, while playing in all 82 games, 43 of them starts.

In game two against the Miami Heat he scored 30 points shooting 13–15 overall from the field (83.3%), including 3–3 in from the three-point line and 1–1 in free throws, with 6 rebounds and one steal in almost 40 minutes played.

[19] In preparation for the 2008–09 NBA season, Nocioni admitted the knee tendinitis which had hampered his performance during the 2008 Olympics was still affecting him and specifically he had hardly done anything in between winning the bronze medal and reporting for training camp.

[20] On February 18, 2009, Nocioni was traded to the Sacramento Kings along with Drew Gooden and Cedric Simmons for John Salmons and Brad Miller.

[22] After the season ended, on June 17, 2010, Nocioni was traded to the Philadelphia 76ers along with Spencer Hawes for Samuel Dalembert.

During the 2011 NBA lockout, Nocioni trained with Peñarol de Mar del Plata while waiting for the situation to resolve itself.

With the announcement of the NBPA to dissolve the Union and start litigation against the NBA, he agreed to join the team for the Súper 8 tournament in November 2011.

[38] In Argentina's game against Nigeria, Nocioni led the team in scoring, with 23 points, playing 18 minutes, while not missing a single shot.

[45] In 2011, he was a part of the team that won the gold medal in the 2011 FIBA Americas Championship, that was played in Mar del Plata.

[47] On February 26, 2018, the Argentine Basketball Confederation retired the #13 jersey worn by Nocioni during his career with the national team.

The ceremony was held in the Parque Carlos Guerrero stadium of Olavarría during the Argentina v. Paraguay match for the 2019 World Cup qualification.