Objective Clinicians commonly fail to weigh patients appropriately in cognitive‐behavioral therapy for eating disorders (CBT‐ED), despite guidelines stressing the need to do so. This study considered the possible patient‐ and clinician‐based reasons why this element of treatment is omitted. Method Seventy‐four CBT‐ED clinicians were presented with vignettes that varied in patient diagnosis and distress levels, to determine whether those characteristics influenced different clinician weighing practices. Clinicians' own attitudes to weighing and their anxiety levels were also assessed to determine whether they were related to weighing intentions. Results Clinicians were more likely to weigh patients with anorexia nervosa than patients with bulimia nervosa, probably due to focusing on physical risk. However, they were less likely to weigh patients who were distressed at the prospect, despite that course of action being particularly clinically indicated. Clinicians were more likely to weigh patients if they had positive beliefs about the value of doing so, and if they were not prone to making unsupported exceptions in delivering this technique. Discussion This study provides evidence that clinicians use weighing differently according to the patient's presentation and their own beliefs, rather than working within guidelines. Education, training, and supervision are suggested to help clinicians address this failure to weigh patients in the most therapeutic way.