He began his professional career at Staatstheater Saarbrücken in 1994 and was soon invited to make debuts in German theaters such as the Stuttgart Opera and Hamburg State Opera, as well as international debuts at the Lyric Opera of Chicago, Opéra National de Paris, and La Scala. He made his Salzburg Festival debut in 1999 in a new production of Busoni's Doktor Faust and returned there in 2003 as Belmonte in Mozart's Die Entführung aus dem Serail and for concerts of the Beethoven's Ninth with the Berlin Philharmonic.
He performed in Covent Garden in 2006-2007 in the role of Don José in Bizet's Carmen to critical acclaim, and also sang Alfredo in Giuseppe Verdi's La Traviata at the Metropolitan Opera and in Covent Garden in 2008. In May 2008, Kaufmann made his role debut as Cavaradossi in Puccini's Tosca in Covent Garden, again to critical acclaim.
In 2008-09 he performed Manon in Chicago opposite Natalie Dessay and in the title role of a new production of Lohengrin at the Bavarian State Opera. He also sang Lohengrin at the Bayreuth Festival opening night performance of the 2010 season; the production was staged by Hans Neuenfels and conducted by Andris Nelsons.
His debut recording with Decca, Romantic Arias, was released in January 2008. He has also recorded a Schubert song cycle on the same label and the role of Pinkerton in Madama Butterfly for EMI.
In January 2010 he assumed the title role in Jules Massenet's Werther at the Opera Bastille; the performance was recorded and released on DVD in November 2010.
In April 2011 he returned to the Metropolitan Opera as Siegmund in director Robert Lepage's new production of Richard Wagner's Die Walküre the second part of his much larger work Der Ring des Nibelungen, scheduled to be presented in its entirety during the 2011-12 season. In September 2011, he underwent surgery to remove a lymph node from his chest.In December, he was back, performing the title role in Gounod's Faust.
On February 15, 2013, Jonas Kaufmann made his first appearance as Parsifal at The Metropolitan Opera.