De Waart became chief conductor and artistic adviser of the Sydney Symphony Orchestra in 1993, and served in the post until 2003.

[2] In January 2008, De Waart was named music director of the Milwaukee Symphony Orchestra, and he assumed the post in September 2009.

[4] In the same month, the Royal Flemish Philharmonic (deFilharmonie) announced De Waart's appointment as chief conductor for six seasons beginning in 2012.

[5] He formally began his chief conductorship of deFilharmonie (now: Antwerp Symphony Orchestra) in 2011, a year earlier than originally scheduled.

In November 2014, deFilharmonie announced that De Waart's tenure as chief conductor would conclude after the 2015–2016 season.

[6] In February 2015, the Milwaukee Symphony announced the conclusion of De Waart's music directorship after the 2016–2017 season.

In January 2019, the orchestra announced the appointment of De Waart as its first-ever principal guest conductor, effective with the 2019–2020 season.

In March 2002, De Waart announced his departure in 2004 as chief conductor of the DNO, a position he had occupied since 1999.

In giving his reason for leaving, De Waart mentioned his desire to spend time with his two small children.

But in an interview with the newspaper Trouw he also mentioned his disagreement with DNO director Pierre Audi's conceptual staging of Lohengrin and Robert Wilson's planned Madama Butterfly, saying he missed "humanity" and "emotion in the direction."

In July 2007, Santa Fe Opera named De Waart their chief conductor, effective 1 October 2007.