Zdenek Košler was a Czechoslovakian conductor who was known for his interpretations of Central European opera and orchestral music. He conducted over 60 orchestras around the world and was a major musical influence in Slovakia.

Košler was born into a musical family in 1928, and had one younger brother, Miroslav, who also became a respected conductor. His father, Vaclav Košler, was a violist in the National Theater Orchestra of Prague, and his mother, Malvina Katzova, was a singer. Both parents contributed to Košler's early musical education with violin and voice lessons. As a boy, he sang in the Kühn Children's Chorus, and he attended the Vancur grammar school in Smíchov. Due to the circumstances of World War II, the Košler family was under the restriction of an 8:00 p.m. curfew set by the Nazis. To keep themselves occupied, they formed a vocal quartet and sang choral music together every evening in their home for three years. Jewish children were banned from attending school, and in 1945 Košler was captured and held in a concentration camp. While imprisoned, the SS discovered that he could play the piano, and they spared his life but forced him to entertain them with nightly performances. After the war ended, he resumed his education at the grammar school and graduated, and then began working as an accompanist and assistant conductor for both the Czech Choir and the Kühn Children's Chorus.

In 1948, Košler joined the Prague National Theater as the accompanist, and enrolled at the Prague Academy of Musical Arts. He majored in conducting, composition, and piano, with professors including Karel Ancerl, Method Doležil, Robert Brock, and Václav Neumann. Leading the Prague Symphony Orchestra, he made his public conducting debut in 1951 at the Prague National Theater, and in 1952 he graduated from the Prague Academy of Musical Arts. Four years later, Košler won first place in the Besançon International Competition, and from 1958 to 1963, he held appointments at the Olomouc Opera, the Ostrava Opera, and the Prague Symphony Orchestra. 1963 proved to be an impactful year for Košler's career when he won the Dimitri Mitropoulos Competition. This granted him the opportunity to serve as Leonard Bernstein's assistant for the 1963-1964 season, which provided him with exposure to a much wider audience.

The resulting publicity led to his appointment as the music director of the Komische Oper, Berlin in 1965, where he remained for three seasons. In 1969 he made his debut conducting in Japan, and he returned annually until the early '90s. He eventually left his position in Berlin in 1971 to conduct on a guest basis for the Slovak National Theatre in Bratislava, and later accepted a five-year residency as director. At this time, he also conducted the Slovak Philharmonic Orchestra, the Czech Philharmonic Orchestra, and several other ensembles throughout Canada, Europe, and East Asia. From 1980 to 1985, Košler led the Prague National Theater Opera, and made some of his most notable recordings including Smetana's The Bartered Bride, Dalibor, Libuse, and Strauss' Tone Poems. Košler retired in 1992 due to health problems but continued to make guest conducting appearances until his death in 1995. He wrote a collection of autobiographical essays, Poselství, that was posthumously published in 1996. ~ RJ Lambert, Rovi