PurposeThis daily diary study aims to examine the influences of daily poor sleep quality on employees’ emotional exhaustion at work via negative affect at home. Additionally, this study examines the moderating effects of day-level customer mistreatment and person-level workplace mindfulness in hotel frontline employees’ daily spillover from the nonwork domain to the work domain.Design/methodology/approachAn experience sampling method was applied, and the survey data were collected from 98 frontline service employees in the hotel industry in China. This study included a one-time initial survey and a ten-day daily diary study.FindingsThis study reveals that frontline service employees’ poor sleep quality of the previous night influences their emotional exhaustion after work through negative affect at home. On days when employees perceived a low level of customer mistreatment, the daily positive association between negative affect at home and emotional exhaustion after work would be attenuated. Moreover, employees with a higher level of workplace mindfulness are less likely to be influenced by the negative affect at home.Practical implicationsThis study suggests that hospitality organizations should extend their focus on caring about employees’ nonwork life quality, such as improving daily sleep quality and providing workplace mindfulness trainings.Originality/valueThis study adds to the current literature on work and nonwork spillover by considering the spillover process from employees’ nonwork domains to work domains by taking a dynamic and multilevel perspective.