In 1975 the University of Queensland Union was granted a radio license to broadcast on the FM frequency range. 4ZZ began transmitting from its studio in the Union Complex on 8 December 1975. It was the first FM broadcaster in Brisbane and the first new radio station in the Queensland capital in over 30 years. On 1 February 1976 the station was remaned 4ZZZ because of a change in the law governing broadcasters using the FM frequency. For its first three months the station broadcast on 1.0 kilowatt Effective Radiated Power (ERP) through an antennae mounted on the roof of the Schonell Theatre, near the studio. 4ZZZ's signal range increased significantly in April 1976 after it began broadcasting on 10.0 kilowatts ERP through a new antennae located on Mt Coot-Tha.

4ZZZ became renowned for its critical journalism, support for independent music and programs which gave a voice to oppressed and marginalised groups. Its newsroom provided a training ground for such notable journalists as Marian Wilkinson, Alan Knight and Stefan Armbruster.

On 14 December 1988, 4ZZZ was forcibly evicted from its St Lucia campus studios by the UQ Union executive led by conservative president Victoria Brazil. Broadcasts continued from a caravan hidden in the forests of Mt Coot-Tha. Although station staff, volunteers and supporters re-occupied the studios and saved the station, the university, it was decided, no longer provided an hospitable environment. On 11 July 1989 the station commenced operating from leased offices in 621 Coronation Drive in Toowong. This, however, was not a viable longterm option. In 1992 the station purchased the former Communist Party of Australia building in Barry Parade in Fortitude Valley and it became 4ZZZ's new home.