The successful treatment of extreme shape concern in patients with eating disorders has been shown to be important for their sustained recovery. This case series reports a preliminary investigation of the effects of a new brief cognitive-behavioural intervention for extreme shape concern. The intervention, which is implemented in a single 2-hour session, addresses four mechanisms hypothesized to contribute to the maintenance of extreme shape concern and is designed to be suitable as an adjunct to existing treatments for eating disorders. Participants were five women with extreme shape concern and three female patients with eating disorders. The results indicate that the intervention was effective to various degrees in each participant, and suggest that the intervention warrants further investigation. In particular, methods of increasing the potency of the intervention should be investigated, and its efficacy tested in a larger controlled study.