PurposeWhile cyberloafing has emerged as a prevalent issue in numerous workplaces, research on its consequences is still underdeveloped, highlighting a need for further exploration and analysis. Drawing upon the cognitive appraisal theory of emotion, this study investigates the influence of coworkers' cyberloafing on employees' workplace incivility, mediated by negative emotions and moderated by task interdependence.Design/methodology/approachIn Study 1, the hypothesized research model was tested utilizing three-wave time-lagged survey data collected from 333 employees and their coworkers. In Study 2, an additional sample of 274 employees was surveyed. Data were analyzed using hierarchical regression analysis and the bootstrap method.FindingsThe results indicated that coworkers' cyberloafing positively influenced employees' workplace incivility, with this relationship mediated by negative emotions. Additionally, task interdependence was found to positively moderate both the direct relationship between coworkers' cyberloafing and negative emotions and the indirect path from coworkers' cyberloafing to employees' workplace incivility through negative emotions.Practical implicationsThis study helps managers gain a deeper understanding of cyberloafing's effects, enabling them to manage and curb it more effectively.Originality/valuePrior research has predominantly explored the effects of cyberloafing on its implementers. However, this study innovatively shifts focus to the observer perspective, empirically demonstrating whether and how coworkers' cyberloafing affects employees' workplace incivility, enriching and expanding the existing literature.