Cognitive-behavioral therapy (CBT-E) is the most widely researched and effective treatment for bulimia nervosa (BN). CBT-E for BN emphasizes the importance of therapeutic skills utilization as consistent skill utilization is proposed to drive treatment outcomes. Despite its theoretical importance, there is limited research on skill use during BN treatment and its impact on BN symptoms. The current study was an exploratory analysis of whether skills utilization during CBT for BN were associated with improvements in BN at post-treatment. Participants (N = 54) with BN-spectrum eating disorders received 16 weekly sessions of individual CBT-E, in which they were taught six core skills designed to reduce BN symptoms. After each session, clinicians rated the degree of skills utilization by participants during the past week. Linear regressions were used to examine whether within-person averages of utilization of each of the six skills were related to treatment outcomes (measured as reduction in binge eating and EDE global scores assessed via the Eating Disorders Examination Global Scale) at post treatment and follow up. Higher average use of all six skills during treatment predicted improvements in global eating pathology at post treatment and follow up. There was no relationship found between skill use and improvements in binge eating at post treatment, however, all six skills except regular eating skill predicted improvements in binge eating at follow up. These findings suggest that greater utilization of skills is crucial in maximizing treatment gains for BN patients. Future studies should explore ways to increase the acceptability and utilization of these skills.