OBJECTIVE: Innovative treatments and outcome measures are needed for binge-eating disorder (BED). This randomized controlled trial compared Integrative Cognitive-Affective Therapy (ICAT-BED), an individual psychotherapy targeting momentary behavioral and emotional precipitants of binge eating, with an established cognitive-behavioral guided self-help (CBTgsh) treatment using standard and ecological momentary assessment (EMA) outcome measures. METHOD: A total of 112 participants were randomized to 17 weeks of treatment (21 sessions for ICAT-BED and 10 sessions for CBTgsh). Binge-eating frequency was assessed with the Eating Disorder Examination (EDE) as well as EMA using cell phone-based real-time, naturalistic assessment at end of treatment (EOT) and 6-month follow-up. Hypothesized maintenance mechanisms were assessed using self-report questionnaires. RESULTS: Binge-eating frequency as measured by the EDE and real-time assessment showed significant reductions at EOT and follow-up, with no significant differences between treatments. Hypothesized maintenance mechanisms, including emotion regulation, cognitive self-discrepancy, self-directed style, as well as measures of associated eating disorder psychopathology, depression, anxiety, impulsivity, and negative affect, showed similar improvement at EOT and follow-up with no differences between treatments. Abstinence rates at EOT (ICAT-BED: 57.1%; CBTgsh: 42.9%) and 6-month follow-up (ICAT-BED: 46.4%; CBTgsh: 42.9%) were not significantly different. Treatment retention was significantly higher for ICAT-BED (87.5%) than CBTgsh (71.4%). DISCUSSION: These findings suggest that ICAT-BED and CBTgsh were associated with similar improvements in binge eating, psychopathology, and putative maintenance mechanisms as measured by traditional self-report and momentary, naturalistic assessments and that these changes were generally sustained at 6-month follow-up.