As Brünnhilde in Harry Kupfer's 1988 staging of Richard Wagner's Niebelungen in Bayreuth, Deborah Polaski emerged as one of the most promising dramatic sopranos. In two consecutive Ring cycles on the “Grüner Hügel” (with Daniel Barenboim 1988, with James Levine 1994), she sang this role more than any other soprano since the Second World War. Although she had already sung in opera houses such as La Scala, Munich and Berlin, it was after her debut in Bayreuth, that she received offers to sing in all of the world’s major opera houses: Paris, London, New York, Sydney, Barcelona, Dresden, Vienna and Salzburg, to name just a few.

Her repertoire comprises primarily dramatic soprano roles, such as the Wagnerian roles of Isolde in Tristan und Isolde, Brünnhilde (Der Ring des Nibelungen), Kundry (Parsifal) and Ortrud (Lohengrin), and Richard Strauss' Ariadne auf Naxos and Elektra, Berlioz' Didon and Cassandre (Les Troyens), Berg's Marie (Wozzeck) and Janáček's Kostelnička (Jenůfa). Many of her Wagner performances are also released on DVD.

In 2003, in recognition of her accomplishment as an artist of distinguished quality and subsequent contribution to Viennese cultural life, the Austrian government rendered her the prestigious title of Austrian Kammersänger. After concluding her active stage career in 2015, she intensified her commitment to teaching, both in master classes and in her private studio.