Purpose We explore whether Machiavellianism - a personality trait which describes the extent to which individuals ignore values and ethical considerations when the ends justify the means - will influence their responses to their employing organizations failure to fulfil promised obligations (psychological contracts). Specifically, we draw on psychological contracts theory and the group value model to argue that Machiavellianism will moderate the relationships between psychological contract breach and (1) organizational identification; and (2) organizational disidentification. Design/Methodology/Approach We tested our hypotheses in a study of 262 employees from various organizations at two points in time. Findings We found that psychological contract breach was negatively related to organizational identification and positively related to organizational disidentification. Furthermore, employees with higher levels of Machiavellianism tended to disidentify with their organizations to a greater extent (at Time 2) in response to psychological contract breach (at Time 1) than did employees with low levels of Machiavellianism. Machiavellianism did not moderate the relationship between psychological contract breach and organizational identification. Implications Our study contributes to extant research exploring the importance of Machiavellianism in the workplace. Specifically, we show that employees with high levels of Machiavellianism are more likely to disidentify in response to psychological contract breach but do not tend to identify to a lesser degree. Originality/Value This study builds on the extant research exploring individual differences in the psychological contract dynamics by considering Machiavellianism as a moderator of the breach-outcome relationship.