PurposeThis study is designed to bridge a gap in the existing leadership communication literature by delving into lesser-explored facets of the field. It particularly concentrates on investigating how the verbal aggressiveness of supervisors influences various aspects of the workplace, including workplace emotional culture, the quality of employee–organization relationships (EORs) and the prevalence of counterproductive work behaviors (CWB).Design/methodology/approachThis study employed a quantitative research design to investigate the impact of supervisors' verbal aggressiveness on employee and organizational outcomes. The data were collected from 392 full-time employees across various organizations and industries in the USA using a self-report questionnaire. The researchers used structural equation modeling (SEM) to analyze the data and test hypotheses.FindingsThe findings of this study showed that supervisors' verbal aggressiveness had a significant positive association with negative emotional culture and employee CWB. However, it had no direct impact on employee–organization relationships. The effect of supervisor verbal aggressiveness on employee CWB was found to be mediated by a negative team-level emotional culture.Originality/valueThis study advances the literature on leadership communication by highlighting the detrimental influence of the dark side of leadership communication. More specifically, by identifying negative emotional culture and employee CWB as the direct outcomes of supervisor verbal aggressiveness, the authors add to the existing theoretical knowledge on verbal aggressiveness in the workplace. Additionally, this study provides empirical evidence of the impact of a negative emotional culture on eliciting employees' CWBs and diminishing relationship quality, adding to the body of knowledge on why managing emotional culture is crucial for organizations and workgroups.