To explore the organizational antecedents of proactive customer service performance (PCSP), we developed and tested a multi-level model of the impact of high-commitment human resource (HR) practices on PCSP in the hospitality industry. Drawing on the proactive motivation model, the mediating roles of work-related self-efficacy, perceived organizational support, and harmonious passion for work are examined simultaneously in the relationship between high-commitment HR practices and PCSP. Using time-lagged data from 94 hotels in China, we found that high-commitment HR practices positively influenced service employees’ PCSP via work-related self-efficacy, perceived organizational support, and harmonious passion for work. We discuss the theoretical and managerial implications of this research and also give some suggestions on how to effectively adopt and implement high-commitment HR practices.