© 2015 Taylor & Francis. This article explores the institutional requirements of accountability for an anticorruption agency in a parliamentary democracy. It suggests that approaching public accountability as ‘the satisfaction of legitimate expectations about the use of discretion’ is useful in understanding or designing an accountability regime for such a powerful agency requiring independence from the executive. The approach facilitates identification of a variety of stakeholders and a range of institutional means by which their legitimate expectations may be satisfied. Despite the recognition, in consequence, of multiple agents and channels of accountability, parliament must remain central to the accountability regime and can achieve this through an appropriately designed oversight committee. Examination of a selected Australian agency, the Western Australian Corruption and Crime Commission, provides support for these propositions. Particular controversies involving this agency are used to demonstrate the requirements of a parliamentary oversight committee, and that independent review of determinations of misconduct, as well as appropriately regulated public hearings where there is a strong public interest in matters under investigation, are important elements of public accountability for an anticorruption agency.