This work seeks to analyse trends, issues and challenges of sustainability reporting by oil and gas companies based in the developed and the developing world. Existing assessment methodologies were reviewed and a framework of assessment was compiled for this study. Twenty-five companies were selected for investigation. This dissertation found that most companies in the developing world are non-sustainability reporters whereas most companies in the developed world are sustainability reporters. The quality of reporting was generally good but there were indications of the need for further research in some areas of sustainability reporting.