This study explores the influence of the qualitative information contained in major customers’ forward-looking management earnings forecast reports (MEFRs) in affecting supplier’s future operating performance in the supply chain. We find the following. First, the qualitative information quality (measured as either textual unreadability or textual uncertainty) of MEFRs issued by major customers has a significantly negative effect on their suppliers’ future operational performance. Second, the qualitative information content (measured by textual tone change) of MEFRs issued by major customers generally has a significant and positive effect on suppliers’ future performance conditional on the qualitative information quality. Third, both qualitative information quality and content of customers’ MRFRs produce greater impacts on supplier’s future performance when supplier has greater analyst following and when supplier’s analysts follow its customers. Further analyses reveal that: (1) the quantitative information quality and qualitative quality customers’ disclosures complement each other in affecting suppliers’ future performance; (2) the effects of both qualitative quality and qualitative content of customers’ MEFRs are stronger for more dependent suppliers and for suppliers with a greater level of sales volatility. Overall, these results indicate not only that the MEFRs of major customers impact their suppliers’ future operating performance but also that this impact is driven by the qualitative characteristics of these reports.