night eating syndrome (nes) is defined primarily by evening hyperphagia, and may be accompanied by morning anorexia, sleep disturbance, and depressed mood that worsens in the evening. it is viewed as a circadian disorder that affects the timing of eating but not the timing of the sleep-wake cycle. nes has been linked to stress, depression, and anxiety, but the role that stress plays in the relation between nes and psychological functioning is not known. most of the previous nes investigations have sampled from clinically obese populations making it difficult to generalize their results to nonclinical populations. the present study looked at stress as a moderator and as a mediator in the relation between nes and depression, state anxiety, sleep quality, and daytime sleepiness in a nonclinical sample of participants. results showed that nes severity was positively related to depression, state anxiety, poor sleep quality, daytime sleepiness and perceived stress. no significant findings were obtained with perceived stress as a moderator. however, perceived stress fully mediated the relation between nes severity and depression, state anxiety, and daytime sleepiness. it also partially mediated the relation between nes severity and sleep quality. the findings suggest that compromised psychological functioning and sleep problems in individuals with nes arise from perceived stress.