Extra - role customer service behavior is of great importance for guest satisfaction in increasingly dynamic and unpredictable competitive environments. Extra - role customer service encompasses discretionary employee behaviors which result in extra a ttention to the guest, the spontaneous delivery of unusual service and, ultimately, a delighted customer. In this study we develop and test a multilevel model of the antecedents of extra - role customer service behavior. We suggest that unit - level psychological safety climate and individual - level self - efficacy jointly predict front - line service employees’ level of engagement in extra - role customer service. We analyzed d ata from 900 front - line service employees and their supervisors in 66 properties of a multinational hotel chain with a random coefficient modeling approach. The results provide support for our three central hypotheses. Based on these results w e discuss important implications for management theory and for practitioners in the hospitality industry