This study aims to characterise Human Research Ethics Committee (HREC) members' perceptions on five main themes associated with ethics reviews, namely, the nature of research, ethical/moral issues, assent, participants' risk and HREC prerogatives issues. Three hundred and sixteen HREC members from over 200 HRECs throughout Australia responded to an online questionnaire survey. The results show that in general, HREC members' beliefs are reasoned and align with sound principles of ethical reviews. There seems to be a disposition for living up to ethical/moral values, avoiding the issue of consent waivers and respecting participants' welfare, as well as a sense of ambiguity about HREC prerogatives. Problematic areas were a tendency towards over-valuing quantitative research methods for their perceived validity and a neutral view on issuing consent waivers to participants with intellectual disability and, finally, the belief that research that limits disclosure, plans deception or actively conceals is morally unjustifiable. Implications for professional development and policy-making are discussed.