In the early 1990s, soprano Ruth Ziesak quickly established an international career in lyric soprano operatic roles, and as a song recitalist and concert singer.
She was born in the scenic Taunus Mountains region of Germany. In 1982 she began her vocal studies with Elsa Cavelti at the Hochschule für Musik und Darstellende Kunst at Frankfurt am Main, Germany. She won a government study stipend in 1986, and in 1987 won the International Walther Grunner Prize in London.
This led to her first professional engagement when she joined the roster of the Stadttheater of Heidelberg in 1988. In 1990 she moved to the Deutsche Oper am Rhein of Düsseldorf-Duisberg. In that year, she also won First Prize in the Lieder category of the 's-Hertogenbosch Competition. She made her debut as a Lieder recitalist in 1991 at the Vienna Konzerthaus.
In 1991, she sang the role of Pamina in Mozart's The Magic Flute at the Salzburg Festival under the direction of Sir Georg Solti. This highly successful performance brought her to international attention. Within the next two years, she debuted at La Scala, the Bavarian State Opera in Munich, the German State Opera in Berlin, the Dresden Semperoper, the Stuttgart Opera, Teatro Communale of Florence, and the Vienna State Opera. In 1993, she sang at the Bastille Opera of Paris for the first time, as Susanna in The Marriage of Figaro. Her Hamburg State Opera debut was in the same year, as the Baroness in Der Wildschütz by Lortzing. Other major operatic roles include Ännchen in Weber's Der Freischütz and Sophie in Strauss' Der Rosenkavalier. Her London debut was as Ighino in Palestrina by Hans Pfitzner, at Covent Garden in a production that was later taken to the stage of the Metropolitan Opera in New York.