Plays in Slovak had been performed as early as 1831 and had played an important role in the process of national revival. However, there were no professional Slovak actors in the early years of the dramatics group of the SND. The first professional actors were Czechs from East Bohemia, who performed in the Czech language. Maryša by the Mrštík brothers was the first play performed at the SND and premiered in March 1920. By May of the same year, the public could see two one-act plays in Slovak by Jozef Gregor Tajovský. In 1921, the first Slovak actors (Bagar, Borodáč, Országhová-Borodáčová, Kello, Arbet and later Hana Meličková) joined the SND. After the arrival of the first professional Slovak director, Ján Borodáč, in 1924, the number of plays being performed in Slovak increased.  Rozdelenie činoherného súboru SND

In 1932 SND’s dramatic group divided into two — the Czech group, headed by director Viktor Šulc, and the Slovak, headed by J. Borodáč. Fruitful communication between the two groups and their directors contributed to their further development. In the 30s Borodáč’s critical-realistic approach acquired a healthy and necessary opposition with the arrival of director Ján Jamnický, an avantgarde artist who understood theatre as a rich inner synthesis of several kinds of art and was inspired by European theatrical personalities, such as Okhlopkov, Tairov, Meyerhold, and Emil František Burian. At that time a young, new generation of actors was also graduating from the Bratislava Academy of Music and Drama and joining the dramatics group, which was becoming increasingly more professional. 

In the changed political conditions of 1938-1939, after the Munich agreement and disintegration of Czechoslovakia, SND’s Czech dramatics group disbanded. Most Czech artists left Slovakia. A galaxy of young actors, who became the ensemble’s pillars in the decades to come, started their careers (M. Huba, F. Dibarbora, K. L. Zachar, V. Záborský, F. Zvarík, L. Chudík, J. Pántik). The number of the directors in the dramatics group increased, as did the production staff. Slovak drama developed (I. Stodola, J. Barč-Ivan, P. Zvon, M. Rázusová-Martáková). During the existence of the wartime Slovak Republic (1939-1945) not only aesthetic but also ideological orientation became polarized in the ensemble. On the one hand there was traditionalist and conservative Ján Borodáč — on the other there were the experimenting, openly critical and democratically oriented Ján Jamnický and Jozef Budský. The dramatics group of the SND became the venue of artistic as well as political confrontation which culminated in the explicit antifascist Slovak National Uprising (1944) 

After the war, in the renewed Czechoslovakia, a generation change took place in the SND. Directors Jozef Budský, Tibor Rakovský, Karol L. Zachar formed the artistic profile of the dramatics group. New authors appeared (Š. Králik, P. Karvaš, L. Lahola) as well as new actors and actresses (M. Prechovská, G. Valach, M. Kráľovičová, C. Filčík, K. Machata, E. Kristínová). Actors, great personalities, who had not been allowed to appear there for political, racial or national reasons, returned to the theatre (A. Bagar, M. Gregor, H. Meličková, R. Porubská). The efforts to make synthetic poetical theatre culminated in several impressive stagings of poetry which evoked a great response in visitors. After the communist coup in 1948 this aesthetic orientation in the SND was forcibly interrupted and the era of ’the only proper ideology’ of Marxism-Leninism and the so-called socialist realism started. 
However, as early as 1956, hand in hand with the first slight lessening of Stalinism, the SND dramatics group returned to its efforts at staging independent works. The creative dialogue of the directors Budský, Rakovský and Zachar determined the period of the second half of the 50s, and the 60s. Budský’s stagings could be characterized by impressive metaphorical theatrical character (Shakespeare: Romeo and Juliet, Čapek: The White Disease, Tchekhov: Ivanov, The Cherry Orchard), Rakovský’s stagings by rational analyses (Brecht: Galilei’s Life, Miller: The View from the Bridge, Karvaš: The Midnight Mass, Shakespeare: Hamlet) and Zachar’s harmonizing artistic style, playfulness and light, detached actor’s approach to the works (Shakespeare: The Merry Wives of Windsor, The Midsummer Night’s Dream, Goldoni: The Fan, Rostand: Cyrano de Bergerac, Palárik: An Adventure at the Harvest Home Festival, Bryll: Painted on Glass). 

In the 50s and the 60s several prominent actors and actresses joined the SND dramatics group (Z. Grúberová, E. Romančík, J. Króner, B. Turzonovová, E. Vášáryová, J. Slezáček, E. Poláková, I. Mistrík, Š. Kvietik, I. Rajniak, M. Dočolomanský) and in the mid 60s young directors Peter Mikulík and Pavol Haspra joined. Mikulík contributed with his typical sense of irony, paradox and grotesque situations (Mrożek: The Turkey, Tango, Vitrac: Victor, Pirandello: Henry IV., Preses & Becher: Bockerer), Haspra did so with his emotional and expressive style (Miller: After the Fall, The Crucible, Albee: Who's Afraid of Virginia Woolf?, Williams: Orpheus Descending).