Corporate social responsibility (CSR) and employees' proactive performance are essential in the hospitality industry, given their positive impact on corporate performance. However, little focus has been given to the influence of CSR on employees' proactive performance. This study utilizes the social information processing theory and proactive motivation model to examine the impact of employees' perceived CSR on their proactive customer service performance. We also investigate the employees' motivational states as mediators, including employees' organization-based self-esteem, felt obligation, and experienced meaningfulness. Empirical evidence is from 438 frontline employees in boutique hotels in China. Results indicate that employees' perceived CSR significantly influences their proactive customer service performance. Specifically, felt obligation and experienced meaningfulness play the mediating roles between employees' perceived CSR and their proactive customer service performance, while organization-based self-esteem does not. This study contributes to the growing body of literature on CSR and employee proactivity, offering practical implications for managers and policymakers who aim to improve employee performance through CSR programs.