Credibility is central to communication but often jeopardized by "credibility gaps." This is especially true for communication about corporate social responsibility (CSR). To date, no tool has been available to analyze stakeholders' credibility perceptions of CSR communication. This article presents a series of studies conducted to develop a scale to assess the perceived credibility of CSR reports, one of CSR communication's most important tools. The scale provides a novel operationalization of credibility using validity claims of Habermas's ideal speech situation as subdimensions. The scale development process, carried out in five studies including a literature review, a Delphi study, and three validation studies applying confirmatory factor analysis, resulted in the 16-item Perceived Credibility (PERCRED) scale. The scale shows convergent, discriminant, concurrent, and nomological validity and is the first validated measure for analyzing credibility perceptions of CSR reports.