NUSAS was founded  in 1924 by members of the Student Representative Councils (SRC) of South African Universities. The union was made up mostly of students from nine white English-language as well as Afrikaans South African universities, and later opened up to all students. Its aim was to advance the common interests of students and its mottos included non-racialism and non-sexism.

In 1945 the first black campus was admitted to NUSAS leading to a walkout by the Afrikaans Campuses. The State clampdown in the early sixties left NUSAS as one of the few organisations who were mobilising opposition against apartheid.

Beyers Naude was the honorary president of NUSAS and Helen Joseph was fondly known as the 'Grandmother of NUSAS'. NUSAS was not only concerned as an organisation with representing students in the political arena. It also concentrated on issues which affected students on a daily basis

NUSAS operated on a national level drawing students of diverse backgrounds and concerns together. By 1990 the Students' Representative Councils on all the 'liberal' campuses were affiliated to NUSAS. NUSAS was also represented through a Local Committee at Stellenbosch University and it had made contact with progressive organisations at the Universities of Pretoria, Port Elizabeth and RAU.

NUSAS was replaced by a non-racial student's organisation, The South African National Students Congress (SANSCO) in the early nineties