His voice matured early into its adult timbre, and at the age of 15, he auditioned for conductor Francesco Molinari-Pradelli, who encouraged him to pursue an operatic career.
After having won the National Competition for young opera singers in Spoleto, he made his debut in the same city in the role of Colline in La bohème in the Festival dei Due Mondi.
Subsequently, an opportunity arose for him at the Teatro dell'Opera in Rome when he was called upon to substitute in the role of Procida in Giuseppe Verdi's I vespri siciliani, and he received enormous success from the public and the critics.
Some of his most important roles have been King Philip in Verdi's Don Carlos; Fiesco; the title roles in Boris Godunov (including the Andrzej Żuławski film) and Attila; Silva; Escamillo in Bizet's Carmen (including the Francesco Rosi film, 1984, with Plácido Domingo and Julia Migenes); the title role in Don Giovanni (including the Joseph Losey film, 1979); Count Almaviva in The Marriage of Figaro; and Don Alfonso in Così fan tutte; the title role in Don Quichotte by Massenet; and Scarpia in a recording of Tosca later filmed live from Rome, with Plácido Domingo and Catherine Malfitano, conducted by Zubin Mehta.
[citation needed] In 2008, Raimondi made his television debut in the mini-series Le Sanglot des anges on French TV, in which he played the role of an Italian opera singer.