Service scripts are behavioral and verbal prescriptions used in many organizations as a way of standardizing employees’ behaviors during their interactions with customers. Yet, they have rarely been studied empirically. There are mixed suggestions in the literature about the beneficial vs. detrimental effects of service scripts. Based on social exchange and citizenship behavior theories, this study investigates whether the relationship between service scripts and an important customer outcome, customer citizenship behavior (CCB), depends on employees’ level of customer orientation. Based on 285 matched dyads of employees and customers from a variety of service organizations, the study found that when service scripts are performed by employees with low customer orientation, service scripts have more detrimental effects on CCB in terms of reducing the propensity among customers to provide unsolicited feedback and their intentions to return to the service firm. There was also support for the mediating role of perceived service quality in accounting for these contingent relationships. These findings contribute to the literature on managing employee behavior and CCB.