Purpose: Guided by the affect theory of social exchange, this study aims to examine the affective process underlying the impact of customer cooperation on hotel frontline employees’ prosocial service behavior. Job autonomy was tested as a boundary condition. Design/methodology/approach: A mix-mode quantitative survey collected data from 818 frontline employees in 14 upscale hotels across China. Data were analyzed using structural equation modeling to test the research hypotheses. Findings: Results suggest that customer cooperation influences employees’ prosocial service behavior directly and indirectly via employees’ positive affect. Contrary to expectations, job autonomy weakened the relationships among customer cooperation, positive affect and employees’ extra-role customer service but did not moderate the impacts of customer cooperation and positive affect on employees’ role-prescribed customer service. Originality/value: As an initial attempt to investigate the effects of customer cooperation on two types of frontline employees’ prosocial behavior, this study broadens the application of the affect theory of social exchange and contributes to an understanding of the theory’s boundary conditions by testing a framework under the contextual condition of job autonomy.