Objective: Cognitive-behavioural therapy (CBT) is an efficacious and effective treatment for eating disorders, and is particularly valuable in the treatment of non-underweight cases (e.g., bulimia nervosa; binge eating-disorders). However, its recommended length for such cases (up to 20 sessions) makes it a relatively costly therapy. It has been suggested that a 10-session version (CBT-T) can also be effective, but there has been no direct comparison between the two forms (10 vs. 20 sessions). Method: This study reports the outcomes of brief and standard-length CBT for non-underweight eating disorders, comparing two cohorts of patients from the same clinic (N = 55 and 138, respectively). Results: The two therapies had very similar results in terms of eating pathology, remission rate, and improved quality of life. Each showed substantial change by the mid-point of therapy and up to 6-month follow-up. Conclusion: It appears that brief CBT (CBT-T) is as effective as existing 20-session CBT, and is less demanding of time and resource. The findings need to be replicated in a randomized control trial before this conclusion can be made definitive.