We wish to acknowledge the funding assistance of the Institute of Chartered Accountants of Nigeria (ICAN) to conduct this study, to which we are grateful to the Council of the Institute for approving the research grant.Sustainability reporting is increasingly being mandated internationally, including in the emerging markets. The latest effort has been a proposal by International Integrated Reporting Council (IIRC) to integrate sustainability and financial reporting. Integrating sustainability and financial reporting presupposes the existence of sustainability reporting knowledge. This study seeks to gain an insight into the views, attitude and understanding of the concept of corporate sustainability and sustainability reporting by the Nigerian professional accountant who is expected to play a role in integrating sustainability and financial reporting in the Nigerian environment. Adopting an exploratory qualitative research design and snowball sampling survey, 1, 857 questionnaires were administered among Nigerian professional accountants out of which 860 usable responses were received. Analysis of the responses show that the accountants understand corporate sustainability as the incorporation of social and environmental concern in business decisions to ensure responsible business practices but within the context of shareholders value maximisation as opposed to being about the right thing to do. According to them sustainability is not about accountants helping corporations to internalise the cost of their externality or providing stakeholders with social and environmental accountability information. This is at variance with its original definition which emphasises meeting the needs of the present without compromising the ability of future generations to meet their own needs. They are of the view that corporations operating in industries with sustainability concerns in Nigeria may not be motivated to engage in sustainability reporting because of lack of public awareness and the non-applicability of most of the business cases for sustainability. As such sustainability reporting should be predicated upon effective regulation, enforcement and sanctions. However, the accountants are favourably disposed to corporations engaging in sustainability reporting; playing some roles in its reporting chain. They support an accounting standard on sustainability reporting as well as Financial Reporting Council of Nigeria (FRCN) mandating it. There is also evidence that the accountants’ sustainability knowledge derives 65% from international linkages and only 1% from the local accounting profession, with a high 24% claiming no knowledge of sustainability reporting. To this end the study recommends that the accounting profession should intervene to equip its members with the relevant knowledge of sustainability reporting and that the corporate reporting regulatory authorities should mandate sustainability reporting in the Nigerian environment.Final Published versio