A previous case-series evaluation of a six-session guided self-help (GSH) approach with 15 people with bulimia nervosa (BN) showed significant reductions across all measures, including binge eating, self-induced vomiting, weight concern, shape concern and dietary restraint. However, the reduction of binge eating and self-induced vomiting was inferior to that achieved in more behavioural approaches. A further 10 people with BN were treated with an eight-session cognitive GSH, where the two extra sessions had a more behavioural focus. Although both conditions significantly decreased levels of binge eating and self-induced vomiting at post-treatment evaluation (with large effect sizes), comparisons of these two GSH conditions showed that an addition of two sessions did not significantly improve outcome on either of the behaviours. Cognitive GSH seems to be a worthwhile candidate for a first-step treatment in BN, but further improvements in this approach can be considered. (Contains 2 tables.)