About 30 staff members were protesting outside the university's Northfields Ave entrance at 9am, but the National Tertiary Education Union (NTEU) said it had no intention of preventing people from crossing the picket line.

Union members are also picketing gates at four other NSW universities - the University of NSW, Macquarie University, the University of Western Sydney, and Southern Cross University.

The dispute centres around demands for a pay rise of between 16 and 18 per cent over three years, as well as the casualisation of staffing at universities.

The union claims staff casualisation is causing significant cutbacks in research and affecting job security.

Earlier this month University of Wollongong (UOW) staff across the board, including academic, administration and building and ground workers, voted to stop work for 24 hours following 18 months of failed negotiations with university management.

At that time, NTEU UOW branch executive member Ron Perrin said more than 80 per cent of staff who voted at UOW favoured strike action - the highest percentage of any university involved.

Mr Perrin said staff were fed up with excessive workloads and increased casualisation and that management was ignoring key issues that affected the quality of education and research.