Amoruso grew up in the Sampdoria youth system, and made his Serie A debut on 12 December 1993, in a 2–0 away defeat to Inter. During his first season with the club he won the Coppa Italia, scoring 3 goals in 8 appearances throughout the competition. He has also later played with Fidelis Andria (1994–95), Padova (1995–96), Juventus (1996–2002), Perugia (1999–2002), SSC Napoli (2000–2001), Como (2003), Modena (2003–04), Messina (2004–05), Reggina (2005–08), Torino (2008–09), Siena (2009), Parma (2009–10), and Atalanta (2010–11).
Amoruso joined Juventus in 1996; he scored 4 goals in Juventus's 1996–97 UEFA Champions League campaign, including one each in both of the semifinal legs against AFC Ajax. He only came on as a late substitute in the final that Juventus lost to Borussia Dortmund, although he as able to captured the 1996 UEFA Super Cup, the 1996 Intercontinental Cup, and the 1996–97 Serie A title with Juventus that season. The following season, he won the 1997 Supercoppa Italiana, and the 1997–98 Serie A title with Juventus. He scored in the return leg of the 1997–98 UEFA Champions League semifinal against AS Monaco FC, but was an unused substitute in the final, as Juventus suffered yet another defeat, at the hands of Real Madrid on this occasion. The 1998–99 season was less successful, as Juventus only managed to capture the 1999 UEFA Intertoto Cup. Amoruso spent the 1999–2000 season on loan with Perugia, and the 2000–01 season on loan with Napoli, beforing returning to Juventus the following season. Amoruso won the 2001–02 Serie A title with Juventus, only making 9 appearances in the league, but helping the club to reach the 2002 Coppa Italia Final, finishing the competition as the top-scorer, with 6 goals. In 2002, he moved to Perugia once again for half a season, and in January 2003, he subsequently played with Como, later moving to Modena for the 2003–04 Serie A season, and Messina for the 2004–05 Serie A season.
In 2004, Amoruso signed with Messina on free transfer, after terminated his contract with Modena.
In 2015 Amoruso signed with Reggina. Along with Rolando Bianchi, they formed an effective striking partner for Reggina's survival battle. In 2007–08 season, Bianchi left the club and Amoruso became the team top-scorer, ahead Franco Brienza and midfielder Francesco Cozza. Reggina almost relegated that season, as ineffective of striker Christian Stuani, Joelson, Stephen Makinwa and Fabio Ceravolo.
On 8 July 2008, he agreed a move to Torino, signed a 2-year contract and reunited with Rolando Bianchi, but during the January 2009 transfer window he transferred on loan with A.C. Siena.
After played the opening match of 2009–10 Serie B season for Toro, Amoruso moved to Parma with Julio César de León and Manuel Coppola move to opposite direction on loan on 28 August.
In January 2010, Amoruso signed a contract with Atalanta B.C. which last until June 2011. Robert Acquafresca, moved back to Genoa from Atalanta, while Hernán Crespo moved to Parma from Genoa. Atalanta also paid Parma €1 million for the service of Amoruso.
He retired in September 2011.
Amoruso represented the Italy under-21 team on 4 occasions between 1994 and 1996, scoring once. He was the unused member of the Italy Olympic team that won the 1997 Mediterranean Games. He also won the 1996 UEFA European Under-21 Football Championship with Italy.Sampdoria
Coppa Italia: 1993–94
Serie A: 1996–97, 1997–98, 2001–02
Supercoppa Italiana: 1997
UEFA Super Cup: 1996
UEFA Intertoto Cup: 1999
Serie B: 2010–11
UEFA European Under-21 Championship: 1996
Coppa Italia Top-scorer: 2001–02 (6 goals)