He translated plays, which most of them are known plays of Bertolt Brecht, stories, novels, books of poems and non-fiction books from German to Turkish and write plays and novels; all published.
As a director, he staged most of Brecht’s works, in a theatre called Epic Theatre which he was one of the frontiers of this theatre movement in Turkey. He was known for staging a known play Fear and Misery of the Third Reich written by Brecht.
- "Son dakika haberi… Tiyatrocu yazar Yılmaz Onay hayatını kaybetti". sozcu.com.tr. Retrieved 14 January 2018.
- "Epik Tiyatro (Marianne Kesting / Çev: Yılmaz Onay)". archive.org. 22 July 2011. Retrieved 14 January 2018.
- Son dakika haberi… Tiyatrocu yazar Yılmaz Onay hayatını kaybetti (in Turkish)