Hollreiser was principal conductor (first Kapellmeister) of the Vienna State Opera from 1952-1961, and was made an Honorary Member of the company in 1991. He made his debut at the Staatsoper with Beethoven's Fidelio in 1951 and went on to conduct over 54 different operas during a four-decade tenure there, ranging from Mozart to 20th-century works. He also led many premieres, including the Austrian premiere of Stravinsky's The Rake's Progress.
Hollreiser was born in 1913 in Munich, where he attended the State Academy of Music. He later served as conductor at the opera houses in Wiesbaden, Darmstadt, Mannheim and Duisburg. From 1942-1945 he served as the principal conductor of the Bavarian State Opera, while also serving as the music director at the Opera in D‹sseldorf.
From 1945-1951 he conducted concerts for the Berlin Philharmonicand Bamberg Symphony Orchestras, as well for the Hamburg, Cologne, and Frankfurt Radio Symphony Orchestras. He also led operas at Covent Garden, Bayreuth, the Teatro Col‹n in Buenos Aires and the Metropolitan Opera during his career and guest-conducted the Vienna Symphony and the Cleveland Orchestra.