Arguably one of the most important developmental milestones in the life of any human is the onset of self-regulation. The development and refinement of attentional control--the top-down regulation of attention to facilitate self-regulatory goals--seems to undergird the capacity to direct behavior, thoughts, and emotions in accordance with one's goals. To date few studies have examined the impact of attentional abilities on day-to-day self-regulation success. This study sought to address this limitation in the literature and examined whether individual differences in attentional control were associated with adolescents' day-to-day regulation of stress-induced negative mood and rumination. Participants drawn from two public high schools in the northeastern United States completed both objective and self-report assessments of attentional control, as well as measures of stress coping. Following these assessments, participants reported on daily experiences of stress, mood, and rumination for 14 consecutive days. Adolescents with higher levels of self-reported attentional control reported less stress-induced negative mood and rumination than adolescents lower in attentional control. Adolescents who performed better on an objective measure of attentional control (Operation Span) also showed less stress-related rumination compared with adolescents who did not perform as well. Results also indicated that involuntary stress responses and perceived stress mediated the associations between attentional control and stress-induced negative mood. Together, the results of this study offer support for the role of attentional control in regulating the emotional and cognitive effects of daily stress.