In 1965, Varviso was appointed music director at the Royal Swedish Opera in Stockholm, a position held for six years. During that time he also frequently conducted at the Bavarian State Opera, the Hamburg State Opera, and the Vienna State Opera. Up until this point he had conducted no Wagner and in 1969 he embarked on an ambitious campaign to add several core Wagnerian works, beginning with "The Flying Dutchman" at the Bayreuth Festival. He returned to the Bayreuth Festival many times, conducting Wagner works during the 1970s and 1980s. (His recorded live performance of "Die Meistersinger von Nürnberg" from the Bayreuth Festival 1974, starring Jean Cox, Karl Ridderbusch, and Hans Sotin is one of the standard-setting recordings of this work, and has been available since the vinyl days.) In 1972, he became the artistic director of the Staatsoper Stuttgart where he served for eight years. In 1974, he took on the same role at the Paris Opera, as well. He worked with the Paris Opéra until 1985. In 1983 he returned to the Met for one last assignment after a 14-year absence at the house. He conducted his final and 147th performance at the house on April 2, 1983 with a production of Wagner's "Die Walküre" with Dame Gwyneth Jones as Brünnhilde and Manfred Jung as Siegmund.