AbstractObjectiveTo examine trajectories of therapeutic skills use and weekly relations between skills use and symptom change during the enhanced version of cognitive‐behavioral therapy (CBT‐E) for bulimia nervosa (BN).MethodFifty‐five adults (M age: 39.0 ± 14.1; 83.9% female; 64.3% White, 93.6% non‐Hispanic/Latino) receiving CBT‐E for BN‐spectrum eating disorders (EDs) self‐monitored their use of five therapeutic skills (i.e., regular eating, eating enough to prevent excessive hunger and eating a range of macronutrients, breaking dietary rules, urge management strategies, and mood management strategies) several times per day during treatment. Patients also self‐reported their ED symptoms (i.e., frequency of binge eating, compensatory behaviors, and dietary restraint) weekly. We examined trajectories of use of each CBT‐E skill and temporal relations between skills use and ED symptoms from week‐to‐week during treatment.ResultsParticipants showed significant increases in eating enough to prevent excessive hunger and eating a range of macronutrients from week‐to‐week (p < .05). Regular eating, eating enough to prevent excessive hunger, and eating a range of macronutrients 1 week predicted lower binge eating and compensatory behaviors the same week and the following week, and urge management strategy use predicted greater binge eating the same week and the following week (p < .05).ConclusionsResults showed temporal relationships between therapeutic skills use and symptom change on a weekly level, with evidence that using skills targeting dietary restraint was associated with lower BN symptoms. Findings highlight the promise of future work to elucidate the most potent CBT‐E skills for symptom improvement and inform more targeted interventions.Public SignificanceFindings showed weekly relationships between therapeutic skills use and symptom change during treatment, with evidence that using CBT‐E skills aimed to reduce dietary restraint (i.e., regular eating, eating enough to prevent excessive hunger, and eating a range of macronutrients) was associated with lower BN symptoms. Future work has the potential to identify the most potent CBT‐E skills for symptom improvement and inform more targeted interventions.