In 1979 he was appointed Music Director of the Oslo Philharmonic Orchestra, with which ensemble he performed, recorded and toured extensively. It was in 1996, whilst in Oslo, that Jansons had a serious heart attack whilst on the podium. He was subsequently fitted with a defibrillator. (Earlier Jansons's father had died while conducting the Halle Orchestra in Manchester). Jansons remained with the Oslo orchestra until 2000. In 1992, he became principal guest conductor of the London Philharmonic Orchestra and in March, 1997, he was appointed music director of the Pittsburgh Symphony Orchestra.
Since 2003 Jansons has been Chief Conductor of the Bavarian Radio Symphony Orchestra and Chorus. After two exceptionally successful seasons his contract was extended in June of 2005 for three additional years until 2009. Mariss Jansons follows Eugen Jochum, Rafael Kubelík, Sir Colin Davis and Lorin Maazel as the fifth Chief Conductor of these two renowned Bavarian Broadcasting ensembles. In 2004 Jansons assumed the position of Chief Conductor of the Royal Concertgebouw Orchestra in Amsterdam.
Mariss Jansons places special emphasis on his work with young musicians. He has conducted the Gustav Mahler Youth Orchestra on a European tour and worked with the Attersee Institute Orchestra, with which he appeared at the Salzburg Festival. In Munich he gives regular concerts with various Bavarian Youth Orchestras and the Academy of the Symphonieorchester des Bayerischen Rundfunks. He is also Artistic Director of the Masterprize Composing Competition.
Mariss Jansons’s discography includes many recordings for EMI, some of which have received prestigious international prizes. The recording of Shostakovich’s Symphony No.7 with the Leningrad Philharmonic won the 1989 Edison Prize and his recordings of Berlioz’s “Symphonie fantastique” and Dvorák’s Fifth Symphony were awarded, respectively, the Dutch Luister Prize and the Penguin Award. In 2005 Mariss Jansons concluded recording his cycle of all the Shostakovich Symphonies, an EMI project in which a number of major orchestras participated.
On January 1, 2006, Mariss Jansons was, for the first time, conductor at the annual New Year’s Concert of the Vienna Philharmonic, which was telecast by 60 different stations on every continent and seen by more than fifty million viewers.