This study examined perceptions of 36 women who participated in Guided Self-Help (GSH) treatment for bulimia nervosa delivered by general practitioners (GPs) in primary care. Qualitative responses revealed factors perceived to contribute toward treatment effectiveness including: improved eating behaviours, body image and emotional and general well-being; the empathic and practical style of the manual; specific behavioural strategies; GP facilitated positive therapeutic alliance and interventions with program implementation; and accessible treatment. Factors perceived as contributing to treatment ineffectiveness concerned: lack of changes to eating and body image; inadequacies of treatment program and approach; inadequate treatment dose; poor service delivery; and perceptions of low GP competence/professionalism and poor therapeutic alliance.