At the age of 11 he entered La Scala Theatre Ballet School.
Rudolf Nureyev was the first to notice his talent and he chose Roberto to interpret Tadzio in the ballet Death in Venice.
In 1996, just two years after he joined the Theatre Company as a member of the corps, at the end of a Romeo and Juliet performance, Roberto was promoted to Principal by Elisabetta Terabust who was at that time the Director of the Ballet.
Since then he has starred in many contemporary and classical ballets such as Sleeping Beauty, Cinderella, Don Quixote (Nureyev), Swan Lake (Nureyev – Dowell – Deane – Bourmeister), The Nutcracker (Wright – Hynd – Deane – Bart), La Bayadère (Makarova), Etudes (Lander), Excelsior (Dell'Ara), Giselle (also in the new Sylvie Guillem's version), Spectre de la rose, La Sylphide, Manon, Romeo and Juliet (MacMillan – Deane), Onegin (Cranko), Notre-Dame de Paris (Petit), The Merry Widow (Hynd), Ondine, Rendez-vous and Thais (Ashton), In the middle somewhat elevated (Forsythe) and Three Preludes (Stevenson).
He has also had many neoclassical roles: Agon, Cajkovsky pas de deux and above all Apollon musagète, which led to his nomination for the “Benois de la Danse” Prix.
Since 1996 his international career has grown enormously. He has danced with the Royal ballet, the National Ballet of Canada, the Stuttgart Ballet, the Finnish National Ballet, the Staatballett Berlin, the Vienna Staatsoper Ballett, the Staatsoper in Dresden, the Munich Ballet, the Tokyo Ballet.
Derek Deane, the English National Ballet director, created two productions for him: Swan Lake and Romeo and Juliet both of them performed at the Royal Albert Hall in London. On the 10th anniversary of the Opera Theatre in Cairo he performed in a fabulous Aida at the pyramids of Giza and afterward on live worldwide television at the Arena in Verona for a new version of the opera.
Since December 1998 he has been Resident Guest Artist at La Scala Theatre.
In October 2000 he opened the season at Covent Garden Opera House in London performing Anthony Dowell's production of Swan Lake and in November he was invited to the Bolshoi to celebrate Majja Plisetskaja's 75th anniversary in the presence of President Putin.
In June 2002, on the occasion of her Golden Jubilee, he danced at Buckingham Palace in the presence of the Queen. The event was broadcast live by the BBC and transmitted to all the Commonwealth countries.
In October 2002 while La Scala Ballet was on tour in Moscow, he danced Romeo and Juliet with Alessandra Ferri in Kenneth MacMillan's production at the Bolshoi Theatre.
In 2003, to celebrate St Petersbourg's 300 year anniversary, Roberto danced Swan Lake with the Royal Ballet at Mariinskij Theatre.
Immediately afterwards he performed Amedeo Amodio's L'après–midi d'un faune to celebrate the return of the Dancing Satyr to Mazara del Vallo (Trapani).
During the 2003/2004 season he was promoted to Etoile at La Scala Theatre.
In February 2004 he performed L'histoire de Manon for the first time with Alessandra Ferri at Arcimboldi Theatre in Milan; it was a huge success.
In March he danced The Fire Bird, a solo made specifically for him by Renato Zanella at the prestigious Italian San Remo Festival, which was broadcast worldwide.
Afterwards he was invited by the Mariinskij Theatre to dance for the third International Ballet Festival where he performed De Grieux in L'histoire de Manon and for the closing Gala he danced the pas de deux from Excelsior and Kudelka's Summer.
On 1st April 2004 he danced in front of the Pope John Paul II in St. Peter's Square to celebrate Young People's Day.
The Paris Opéra invited him to dance Don Quixote in May and The Sleeping Beauty in December.
On 7th December, to celebrate the re-opening of La Scala Theatre after its restoration, he danced Europa riconosciuta with Alessandra Ferri and three weeks later in the New Year's Eve Star Gala.
In March 2005 he was invited to dance Apollon musagète at the Mariinskj Theatre in St. Petersburg on the occasion of the fourth International Ballet Festival.
In December 2005 at Covent Garden Opera House in London he performed Federick Ashton's production of Sylvia, broadcast by the BBC on Christmas Day.
In February 2006 he danced at the opening ceremony of the Winter Olympic Games in Turin where he performed a solo created for him by Enzo Cosimi. The ceremony was broadcast worldwide and seen by 2.5 billion people.
Among his numerous partners: Altynai Asylmuratova, Darcey Bussell, Lisa-Marie Cullum, Viviana Durante, Alessandra Ferri, Carla Fracci, Isabelle Guérin, Sylvie Guillem, Greta Hodgkinson, Margareth Illmann, Susan Jaffe, Lucia Lacarra, Agnès Letestu, Marianela Nuñez, Elena Pankova, Lisa Pavane, Darja Pavlenko, Laetitia Pujol, Tamara Rojo, Polina Semionova, Diana Vishneva, Zenaida Yanowsky, Svetlana Zakharova.
In 2007 he performed for the first time as a guest artist with ABT, on the occasion of Alessandra Ferri's farewell performance.
For the 2009 Spring Season at the Metropolitan Opera House in New York, he performed as a Principal Dancer with the American Ballet Theatre: it was the first time that a male Italian dancer had joined the Company as a Principal.
Since 1999 he has been a Goodwill Ambassador for UNICEF and in 2006 he visited Sudan on his first trip into the field.