This study investigated the main effects and the interaction effects of psychological contract breach and hostile attributional style on employee deviance (i.e., interpersonal deviance and organizational deviance). Data were collected from 233 employees and their supervisors in eight electronic companies in Taiwan. Results demonstrate that psychological contract breach related positively to both interpersonal and organizational deviance. Psychological contract breach did not have a stronger effect on organizational deviance than on interpersonal deviance. Hostile attributional style had interactive effects on the relationships between psychological contract breach and the two forms of employee deviance. Specifically, the higher the hostile attributional style, the stronger the positive relationship between psychological contract breach and employee deviance. This study contributes to the existing literature on reactions to psychological contract breach. We discuss theoretical and practical implications of the study results and future research directions. (Contains 2 figures and 2 tables.)