The Integrated Reporting (IR) Framework of 2013 represents the latest international attempt to connect in one company report a firm’s financial and sustainability (i.e. environmental, social and governance) performance. An IR should communicate “concisely” about how a firm’s strategy, governance, performance and prospects, in the context of its external environment, lead to the creation of sustainable value. At the same time, an IR needs to be “complete”, i.e., broadly including all material matters, both positive and negative. Drawing on impression management studies, we examine a selection of performance determinants to gain insights into the factors associated with conciseness and completeness in IR. The results from a sample of IR early adopters show that in the presence of a firm’s weak financial performance, the IR tends to be significantly longer and less readable (i.e., less concise), and more optimistic (i.e., less complete). We additionally find that firms with worse social performance provide reports that are foggier (i.e., less concise) and with less information on their sustainability performance (i.e., are less complete). Our evidence implies that IR early adopters employ quantity and syntactical reading ease manipulation as well as thematic content and verbal tone manipulation as impression management strategies. The results also suggest that such strategies not only depend on the level of firms’ performance, but also on the type of performance (financial versus non-financial/sustainability). This paper adds to the limited literature on IR in sustainability accounting, as well as to research in mainstream financial accounting that examines disclosure quality using textual analysis Saying more with less? Disclosure conciseness and completeness in Integrated Reports. Available from: https://www.researchgate.net/publication/309557517_Saying_more_with_less_Disclosure_conciseness_and_completeness_in_Integrated_Reports [accessed Mar 31, 2017].