This study examines the impact of psychopathic and narcissist personalities on employees' adverse outcomes. Additionally, this study investigates the intervening mechanism of workplace incivility among the relationship of psychopathic and narcissist personalities and adverse outcomes. Furthermore, the interactive impact of Islamic work values was also tested between the association of workplace incivility and adverse outcomes. Using the purposive sampling technique, data was collected through a survey method from 404 permanent employees of a public sector organization in two different time-lags. PROCESS-macro was used to test indirect, interactive, and moderated mediation effects. The findings of this study confirm the direct effect relationship between that psychopathic and narcissist personalities and employees’ adverse outcomes. Further, this study confirms that workplace incivility indirectly enhances the adverse outcomes of employees. Finally, the study findings revealed that a higher level of Islamic work values reduces the adverse outcomes of the employees having psychopathic and narcissist personality characteristics. We also tested moderated mediation model, which disclosed that a higher level of Islamic work values reduces the negativity level of psychopathic personalities that further decrease the level of counterproductive work behaviors via workplace incivility. However, there was no moderating role of Islamic work values to reduce narcissist personalities' negativity level and reduce counterproductive work behaviors via workplace incivility. The present study by providing information to the management of the public sector organizations on how they can overcome the negative behaviors and outcomes of their workforce through the implementation of the Islamic ethical system. This attempt contributed to ethical climate theory and threatened the egotism model by explaining that negative personality traits predict uncivil behaviors, which further lead to adverse outcomes. This study further contributes that the ethical climate of the organization helps the individuals to overcome the negativity of the personality and negative behaviors as well.