As part of its public service mission, TNSJ's main objectives are the creation and presentation of theatre performances of various genres, in accordance with standards of artistic and technical excellence, and the promotion of regular contact between audiences and the classic and contemporary reference works of the national and universal dramatic repertoire.

Considering theatre to be the art par excellence of embodying and transmitting the word, the TNSJ's programme is based on the defence of the Portuguese language and Portuguese-language dramaturgy, in both its standard and polymorphic forms, including its dialectal variants. This priority runs through the training programmes for interpreters, the direction of actors and the demanding quality of the texts, whether written originally or in translation.