The purpose of this study was to investigate the effect of managerial overconfidence as a behavioral bias on the tone of management reports, including directors’ report and management discussion and analysis (MD&A). In this research, the frequency of technical words was used to measure the tone of the management report, and overinvestment was used as a proxy for managerial overconfidence. The hypotheses were tested on 134 companies over a 4-year period from 2017 to 2020, using multivariate regression models in STATA. The results show that managerial overconfidence is not significantly associated with the positive tone of management reports, but is positively associated with the negative tone of these reports. The results suggest that, due to the uncertainties and risks in the economic environment of Iran and their escalation within the time frame of the present research, overconfident managers tend to use a more negative tone when reporting on risks and uncertainties to avoid the negative consequences of overstatement. Manuscript profile