The in 1962 in Bacău born actress finished the Nikolaus Lenau Secondary School in Timişoara in 1980 and then studied German studies at the University in Timişoara. After being a teacher until 1988 she became an ensemble member of the German State Theatre Timişoara. Between 1992 and 1996 she studied acting at the German section for acting at the Music department of the West University Timişoara, year Ida Jarcsek-Gaza.

These are some of her many roles she performed at the German State Theatre Timişoara:

- Stella, in Stella by Johann Wolfgang Goethe, director: Frieder Lorenz (Germany);

- The Dog, in The Town Musicians of Bremen after the Brothers Grimm, director:

 Stephan-Andreas Darida;

- Widow Bolte, Storyteller, in Max and Moritz, by Wilhelm Busch, director: Ida Jarcsek-Gaza;

- Venus of Rosalba, in The Italian Straw Hat, by Eugene Labiche, director: Stephan-Andreas Darrida;

- Elena Ivanovna, in The Bear, by A.P. Cekhov, director: Andreas Poppe (Germany);

- Zilla, in Portrait of a Planet, by Friedrich Dürrenmatt, director: Ida Jarcsek-Gaza;

- Raina, in Arms and the Man, by G.B. Shaw, director: Martin Baucks (Germany);

- A Woman, in Don Juan Comes  Back from the War, by Ödön von Horváth, director: Martin Eickel (Germany);

- The Old Musician, in Wolves, by Theodor Smeu-Stermin, director: Theodor Smeu-Stermin;

- Bärbl, in The Godfather, by Adam Müller-Guttenbrunn, director: Stephan-Andreas Darida;

- Choir, in Electra, by Sophokles, director: Cristian Hadji-Culea;

- Sophie, in Intrigue and Love, by Friedrich Schiller, director: Clemens Bechtel (Germany);

- Elisabeth Roller, in The Robbers, after Friedrich Schiller, director: Clemens Bechtel (Germany);

- Mother, in Red Riding Hood, Red Riding Hood, by Ernst A. Ekker and Sergej Dreznin, director:  Marina Tiron-Emandi;

- Gladys, in Out of Order, by Ray Cooney, director: Bogdan Ulmu;

- Peasant Woman, in Mother Courage and Her Children, by Bertolt Brecht, director: Victor Ioan Frunză;

- Governess, in Leonce and Lena, by Georg Büchner, director: Bogdan Ulmu;

- Cornelius, in Cymbeline, by William Shakespeare, director: Alexander Hausvater;

- The Mother, in Fireface, by Marius von Mayenburg, director: Radu-Alexandru Nica.

She also worked as Assistant Director for Andreas Poppe, Frieder Lorenz, Bogdan Ulmu and Rolf von Parchwitz, just to name a few.

Since 1998 Isolde Cobeţ has extensively worked in the field of School and Youth Theatre. She leads the Nikoluas Lenau Lyzeum's after-school drama group NIL. With this group she realised various plays, some of them in her own translation – for instance: Romeo and Juliet, by Williams Shakespeare, The Island, by Mihail Sebastian, Dorogaya Yelena Sergeevna, by Lyudmila Razumovskaya, Always Ultra, by C. Schäfer, all of which earned prizes at Youth Theatre Festivals.

Production with the NIL Theatre group:

- Romeo and Juliet by William Shakespeare

- Summer of Aviya by Gila Almagor

- Dorogaya Yelena Sergeevna by Lyudmila Rasumovskaya

- The Island by Mihail Sebastian (translated into Romanian by Isolde Cobeţ)

- Is Corinna Guilty by L. Fulga (translated into Romanian by Isolde Cobeţ)

- Discord of the Gods, collage of monologues from Greek tragedies

- Undine by J. Giraudoux

- Shadow Carousel, collage of poems of World literature

- Antigone by J. Annouilh

- Faust after Goethe

- Morales and Hocus-Pocus, collage of monodramas by A. Cekhov

- After Juliet Vin by Sh. MacDonald

- Tattoo by Dea Loher

- Colours::: Dreams:: Life… by Bubu and Iso

- Faust on the Hunt for True Love after Goethe

- The White Magnolia, collage of Horvath, Plenzdorff, Goethe, Lorca

1998 she took an internship in the field of theatre pedagogy at the "Theater im Zentrun" in Stuttgart. From 2000 until 2004 she gave speech training and taught theatre history and acting for the German Acting class of the Ion-Vidu Art Lyceum in Timişoara. In 2000 she was Artistic Director of the Pupil's Theatre Festival "Babylon – Europe is meeting up" in Bayreuth (Germany). She participates in organizing the annual International German-speaking Lyceum Theatre Festival in Timişoara.and is leading workshops at School theatre festivals in Romania, Germany, Hungary and Croatia.

Since 2008 she is leading the student theatre group "AFTER Nil", which performs in German.

From 2006 until 2007 she taught at the Catholic University Budapest at the department for theatre pedagogic: improvisation, speech training, acting, movement and communication in German.

Between 2000 and 2002 as well as between 2004 and 2009 she was Artistic Director of the International German-speaking Lyceum Theatre Festival.