In this study we combined daily diary data with interview data to investigate individual differences in the impact of stressful daily events on mood. Using a sample of 96 women in an urban community, we examined perceived neighborhood quality and major life events as possibly potentiating the effects of stressful daily events, and we viewed social supports as potentially buffering this daily process. Results confirmed that the presence of chronic ecologic stress (neighborhood perceptions) exacerbated the immediate effects of stressful daily events on mood and also increased the likelihood of enduring effects of daily stressors on next day's mood. Contrary to expectations, previous exposure to major life events decreased the impact of stressful daily events. The availability of social supports, although not buffering the impact of stressful daily events on mood, did mitigate the enduring effects of these events on next day's mood. This study also presents a method for analyzing daily time-series data, while correcting for potential problems ofautocorrelated error terms. As such, this study represents a significant advance over previous analytic approaches to time-series data in the study of the stress process.Some days everything seems to go wrong, and by day's end, minor difficulties find their outlet in rotten moods. This basic feature of daily life is increasingly attracting the attention of researchers concerned with assessing the relation of environmental stressors to psychological distress. The recent emphasis on daily events is due, in part, to the extensive criticism directed at traditional approaches to the study of environmental stress.The major life events approach assumes that there is a temporal association between an increase in objective events such as divorce and unemployment, which disrupt an individual's usual activities, and the onset of psychological distress. This approach has been criticized from several fronts. The psychometric properties of life-event questionnaires are seldom adequate (Neugebauer, 1981); measures of undesirable life events and outcome criteria may be operationally confounded (Thoits, 1981); and the predictive validity of life event measures is, at best, moderate (Rabkin & Struening, 1976).In contrast to the major life events approach, stress researchers are increasingly attending to the ongoing stressors and strains that characterize everyday life and their relation to psychological functioning. Daily stressors range from the ordinary troubles of family life (e.g., the demands of children) to conflicts in the workplace (e.g., work overload) and aspects of the physi-