This paper reviews the experience of 174 of Canada's largest 1500 public and private sector corporations which have begun to incorporate sustainable development management and reporting as part of their operations. Answers are provided to three main questions: Why have they implemented this initiative? What progress has been made in terms of sustainability audit practice – frequency, focus, organization of the audit team –, internal communication, and external reporting? And where has, and will the leadership for the sustainability audit movement come from as why? Sustainable development auditing and reporting in Canada is voluntary. Practice varies from an elementary level to a sophisticated integrated assessment of social, environmental, labour, sourcing and trading, and governance issues. The depth of practice and experience in this area depends on several factors, including: corporate commitment, the degree of public perception of sector-wide environmental issues, exposure to legal liability, and the extent of dialogue and transparency associated with the auditing process. Differences of opinion about accounting and auditing standards as well as whether all, or parts of, audits should be independent are explored. The sources of data used for this paper include the EthicScan Corporate 1500 DataBase, The Corporate Ethics Monitor1, various reports prepared by EthicScan Canada, and the consultancies of both authors.