Researchers have stressed the importance of assessing individual differences in personality as an approach to understanding aggressive and deviant conduct across different contexts. This study investigated the moderation role of irritability, a specific aggression-related disposition, in the process of work stressors that are conducive to counterproductive work behavior (CWB) within the stressor-emotion model. From a total sample of 1,147 Italian workers (53.5% women), high-and low-irritability groups were identified. Then, using a multi-group structural equations model, we simultaneously examined all the relations in both high-and low-irritability groups, and investigated whether these relations were different between them. Results showed that job stressors elicited negative emotions that, in turn, lead to CWB. Moreover, only in high-irritability group some job stressors influenced CWB also directly. Overall irritability moderated mainly the relation among job stressors and CWB but not the relation among job stressors and negative emotions, with the only exception of role conflict. As well, irritability did not moderate the relation between emotion and CWB. Thus, high-irritability employees may be more prone to react aggressively to job stressors via multiple functioning paths. The principal differences between low-and high-irritability individuals could be how they manage the impact of perceived stressors on emotions and behavior.