This study investigates the impact of crowding on frontline service employees. In particular, this study examines how customer crowding affects frontline service employees’ stress, emotions, job performance, and displayed emotions. This study pioneers a new avenue by investigating employee (as opposed to consumer) reactions to customer crowding and addressing the gap in the literature on employees’ interaction with the physical environment. The underlying theoretical framework of the study is rooted in Lazarus’s (1966; 1991) model that links appraisal, emotional response, and coping in a sequential process. Applying theory to the context issue of customer crowding, the major constructs for this study are determined as: 1)the stressor (customer crowding), (2)appraisal,(3) emotions, (4)coping, and (5)service quality outcomes. The four major areas investigated in this study are: (1)stress levels of FSE due to customer crowding, (2)their emotions in the crowded service environment, (3)coping strategies they use under these circumstances, and(4)effects of such coping strategies on job performance and displayed emotions. A laboratory experiment is conducted with 200 frontline service employees where human density (a precursor to crowding)is manipulated via scenarios and videos. Analyzing the data via ANOVA, simple regression, and multiple regression, the results showed: (1)a positive relationship between crowding and stress, (2)an inverse relationship between positive emotions and stress, (3)a positive relationship between stress and negative emotions, (4) a negative impact of escape and confrontive coping strategies on service quality outcomes, and (5) a positive impact of distancing and social support on service quality outcomes. The contributions of the study are that: (1)it pioneers a new research avenue which opens avenues for future research, (2)it goes beyond the traditional Stimulus-Organism-Response approach to person-environment interaction and expands the domain of inquiry by incorporating the Lazarus transactional theory in the study of person-environment interaction, and (3)it provides a number of managerial implications regarding design of servicescapes to reduce the experience of crowding and training of frontline service employees on successful coping strategies.