Purpose: The purpose of the article is to present the author’s own comprehensive method of testing impression management in narrative reporting and the possibility of using it to evaluate and measure impression management and identify the strategy of impression management in letters to shareholders. Methodology/approach: The development of the method of testing impression management in narrative reporting was preceded by a critical analysis of the literature. Content analysis and the IMNR (impression management in narrative reporting) index were used in the empirical study. The study covered ten letters to shareholders of Polish companies. Findings: The article presents a tool for assessing and measuring impression management, showing how it is calculated. It also presents the results of a survey, showing the possibilities of using the IMNR index. In the audited board of directors’ letters, the occurrence of all analysed impression management strategies was identified. The article discusses selected methods of impression management observed in those documents. Research limitations/implications: The proposed IMNR index is limited to selected impression management strategies and the means by which they can be detected. As the study was limited to selected companies, future research may investigate other entities or reporting forms. Additionally, only documents written in Polish were analysed. Originality/value: The article presents the original IMNR index, which makes it possible to comprehensively examine impression management and compare reports. The conducted empirical study covered a wide range of ways of managing impressions. Documents written in Polish were examined. As Polish researchers have been dealing with the issue of impression management by Polish companies since only relatively recently, the research gap, which this article partially fills, is extremely wide.