In general, social, environmental, and sustainability disclosures are not regulated by legislation or accounting standards in Australia. Despite their discretionary nature, companies expend significant time and money on making sustainability disclosure. This study raises the question whether a firm that has high quality sustainability disclosure does indeed have a high sustainability performance. That is, is sustainability disclosure part of a cynical public relations exercise, or is this disclosure reflective of a firm's commitment to sustainable operations? Stakeholder theory is used to place the level of a firm's sustainability disclosure in the context of its level of sustainability performance, the power of its stakeholder groups, the firm's strategic posture on stakeholder management, and the firm's economic performance. The research question and subsequent hypotheses are investigated using a randomly selected sample of companies operating in the Australian extractive industry in 2006. The results of this study indicate that higher levels of sustainability disclosure are strongly associated with sustainability performance. Additionally, the overall results show that higher stakeholder power, active strategic posture and better economic perfoffi1ance also increase the level of sustainability disclosure.