OBJECTIVE Naturalistic studies on sufferers of bulimic syndromes suggest that binge episodes are often precipitated by episodes of dietary restraint. However, evidence also implies that binge eating may, in certain psychopathological contexts, have less direct connection with dietary control factors. Applying an 8- to 22-day experience-sampling procedure in individuals with bulimic syndromes, we explored possible moderating effects of trait impulsivity upon the ongoing association between cognitive dietary control and binge eating. METHOD Fifty-one women with bulimia spectrum eating disorders provided periodic daily observations on cognitive control over eating, urges to binge, and binge episodes. Impulsivity was assessed by self-report questionnaire. Hierarchical linear modeling techniques were used to assess relationships of interest. RESULTS Urge to Binge was higher (on average) prior to eating binges than at comparable times on binge-free days, and thus seemed to signal the potential for binge eating. More importantly, scores on Urge to Binge and Dietary Control covaried systematically over time in most participants, but were desynchronous in highly impulsive individuals. CONCLUSIONS Binge eating is closely linked to dietary control in most bulimic individuals, but this may be less typical of individuals showing marked impulsivity. We discuss factors that may explain the disconnection between Dietary Control and Urge to Binge in impulsive binge eaters as well as the implications of such factors for the management of bulimic patients with marked impulsivity.