Since the 1940s, advocacy of the establishment of audit committees was undertaken by regulatory agencies, and subsequently by the accounting profession, and committees representing combinations of interest groups. Over time, this advocacy literature has reflected changing views about the key responsibilities of audit committees. Initially, audit committees were primarily concerned with negotiations with (or responding to) auditors, and reviewing financial statements prior to publication. Since the 1970s, formal guidelines or requirements have suggested additional responsibilities that involve oversight of the internal management of corporations. There is a pattern of renewed enthusiasm for enhanced corporate governance and for a stronger role for audit committees following spates of corporate crashes or disasters. Nevertheless, some of the lessons from those events continue to be ignored, so that arguably there are gaps in contemporary guidelines on audit committees. These gaps concern the need for audit committees to review the structure and design of delegations, and the adequacy of financial and operational information being provided to senior management and boards (particularly concerning subsidiaries and associated entities). These gaps are also reflected in the charters of the audit committees of Australia's top 200 listed entities. However, in some respects, Australian practice has gone beyond the recommendations embodied in recent guidelines. Drawing from literature and practice, this article proposes a model charter which, if adopted, may contribute to improvements in the effectiveness of audit committees.