The hypothesis that negative daily events mediate the relationship between major negative events and psychological symptomatology was tested using a three-wave, three-variable panel design. Measures of major and daily life events and psychological symptomatology were administered to 58 older adolescents at three time points during the transition from high school to college. The results indicated that the pathways from major life events to daily events and from daily events to psychological symptomatology were significant at each of the time points, but that the direct pathways from major events to psychological symptomatology were not significant at any time point. Thus, the hypothesis was fully supported. The findings are discussed in light of their implications for an integrative theory of the process by which major and daily events have an effect on psychological symptomatology.