It was established in the 1950s and was the first professional theatre for children and youth in Slovenia. In the 1980s Mladinsko Theatre initiated a unique interdisciplinary research on stage, and its productions („Missa in A Minor”, “The Class Enemy”, “Romeo and Juliet”, “The Persians”, “Ana”, etc.) were to be widely acclaimed for their political engagement as well as for their innovative approach to mis-en-scene.
For the the last two decades, Mladinsko Theatre has been working with stage directors whose dialogue with dramatic texts and personal poetics was deemed inventive and avant garde (for example Vito Taufer, Matjaž Pograjc, Dragan Živadinov, Eduard Miler, Diego de Brea, Jernej Lorenci, Ivica Buljan).
In 2007 the SMG celebrated its 50th anniversary, publishing an illustrated book about its history. Mladinsko Theatre regularly makes guest performances at international festivals worldwide (Nancy, Hamburg, Belgrade, London, Moscow, Essen, Cardiff, Lisbon, Madrid, Bogota, New York) and also hosts selected performances from other countries.