This study builds upon prior research on associations between moods, family functioning, and binge eating, using ecological momentary assessment to examine moderating effects of family functioning on associations between moods and binge eating. This study was conducted among a nonclinical sample of urban adolescents. Family functioning was assessed using five constructs adopted from the FACES-IV measure: 'family cohesion,' 'family flexibility' 'family communication,' 'family satisfaction,' and 'family balance.' Mood data was gathered using 13 items from a daily affect scale. Binge eating was assessed using two subscales from the Eating Disorder Diagnostic Scale-binge eating associated with 'embarrassment' (BE1), and binge eating associated with a sense of 'loss of control' (BE2). A multilevel modeling approach was employed to examine how associations between momentary moods and binge eating behaviors were moderated by family functioning. Results indicated that measures of negative affect, stress/frustration, and tiredness/boredom were significantly and positively associated with two measures of binge eating (BE1 and BE2; p values ≤ 0.05), and that multiple factors of family functioning buffered the positive predictive effects of moods on binge eating. Findings indicate the importance of inclusion of family functioning in the development of eating behavior interventions for adolescents.