Multinational mining companies operating in Latin America increasingly publish sustainability reports which outline their contributions to sustainable development. Companies argue that reports help communities better understand the importance of the benefits created by mining. However, we argue that sustainability reporting can only play a role in improving a company's performance and reputation if the quality of the reported data is good enough to answer community-raised contentious issues and if such are tackled through a stakeholder engagement process which includes 'anti-mining' groups. The paper examines a mining conflict in Argentina's Bajo de la Alumbrera open pit mine. The assessment is based on a content analysis of Alumbrera's Sustainability Report (SR), primarily from 2009, complemented with insights from the 2010 and 2011 reports. The study reveals that environmental and economic indicators are the most contentious and least reported. The reports examined only briefly acknowledge these issues, and fail to detail the procedures followed to identify and engage stakeholders.