Objectives - To investigate the extent to which compliance with treatment is related to outcome, and factors associated with compliance in a group of treatment-resistant eating-disordered in-patients. Design - A retrospective case study design was employed where clinic staff made expert ratings of eating behaviours, attitudes and outcome of former in-patients. Method - Ten health-care staff at a specialist eating disorders clinic rated overall success of treatment outcome at discharge, as well as compliance, severity of disordered eating behaviours and body-image disturbance at both admission and discharge for 46 anorexic and 14 bulimic patients. Results - For all participants, high compliance at admission was associated with lower levels of body image disturbance, less disordered eating behaviours and higher ratings of overall treatment success at discharge. Compliance at admission predicted the body mass index (BMI) at discharge for anorexic participants and predicted higher ratings of overall treatment success at discharge for all participants. In all participants, compliance at admission was related to the extent of eating-disordered behaviours at admission. Conclusions - Results suggest the importance of compliance in facilitating recovery and treatment success among treatment-resistant eating-disordered in-patients. The promotion of strategies to improve compliance in this population should be considered. A role for motivational interviewing is discussed.