Agnieszka Kreiner was born in Krakow (Poland). She studied biology at the Jagiellonian University and, at the same time, at the Academy of Music in Krakow. She completed her studies with maestro Igor Markevitch in Saint Cézaire (France) in 1975. Agnieszka Kreiner graduated in 1980 the Hochschule für Musik und Darstellende Kunst in Vienna (under Prof. Otmar Suitner).
In 1974 she won the third prize at the Grzegorz Fitelberg National Competition for Conductors in Katowice.
Agnieszka Kreiner started her professional career in 1973 as a soloist's coach at the Silesian Opera, and then she became a conductor of the Krakow Opera.
From 1982 to 1992 ms. Kreiner was engaged as a conductor of the Grand Theatre (National Opera) in Warsaw. During this period she conducted over 250 performances (including world premieres). She made as well touring to Germany (Dresden, Kiel, Karlsruhe), Russia (Moscow), France (Paris), Luxembourg and Netherlands.
She has conducted orchestras in Vienna (N. Tonkünstler), Wiesbaden (Hessisches Staaatstheater), Weimar, Krakow, Poznan, Warsaw, Bromberg, Toruń, Lublin, Rzeszow, Olsztyn, Koszalin and Katowice.
From 1994 to 1997 Agnieszka Kreiner was the artistic director and chief conductor of State Philharmonic in Lublin. She conducted there many symphonic works of Polish contemporary composers as Lutosławski, Panufnik, Górecki, Penderecki, organized Young People's Concerts and Music Festival. In 1997 she recorded the CD including Polish symphonic music.

In 2004 she has organised Tatra Chamber Orchestra in Zakopane. The ensemble has already performed in Zakopane,Cracow, Warsaw, Lublin, Gdansk, Olkusz and Strzegom.
She published music handbooks: for secondary school (in 2000), elementary school (in 2002) and for music school (2006).

In 2006 Agnieszka Kreiner resumed her cooperation with the Silesian Opera in Bytom where she now appears regularly. In 2006 and 2007 she performed G.Verdi’s Nabucco with Silesian Opera ensemble in Germany and Netherlands.