Corporate sustainability reports are supposed to provide a complete and balanced picture of corporate sustainability performance. They are, however, usually voluntary and thus prone to interpretation and even greenwashing tendencies. To overcome this problem, the Global Reporting Initiative (GRI) provides standardized reporting guidelines challenging companies to report positive and negative aspects of an organization’s sustainability performance. However, the reporting of “negative aspects” in particular can endanger corporate legitimacy if perceived by the stakeholders as not being in line with societal norms (...) and values. Starting from the theoretical lenses of economics-based disclosure theories and socio-political theories of disclosure, the focus of this study therefore was to analyze the communicative legitimation strategies companies use to report “negative aspects,” i.e., negative ecological and social impact caused by corporate activity. Using qualitative content analysis of GRI-oriented sustainability reports from companies listed on the US Dow Jones Industrial Average Index and on the German DAX Index, we identified six legitimation strategies. We discuss these strategies regarding to symbolic and substantial management of legitimacy. We show that symbolic legitimation strategies aiming at modifying the perception of legitimizing stakeholders dominate in the reports at hand. Such persuasion, however, does not meet the requirement of impartiality as postulated by the GRI guidelines. Building upon this conclusion we propose a concise characterization of “negative aspects” and develop a GRI-compliant schema of reporting about them. In doing so, we offer a way to improve the overall “balance” of sustainability reporting contributing to a true and fair view in sustainability disclosure. (shrink)