AbstractObjectiveThe present study aimed to investigate the impact of Body Mass Index (BMI), duration of illness and severity of illness on quality of life within a sample of individuals in treatment for an eating disorder. In addition this study explored differences in specific areas of quality of life (Psychological, Physical/Cognitive, Work/School and Financial) according to specific eating disorder diagnoses.MethodParticipants (N = 156) were adults currently receiving treatment for an eating disorder. Eating disorder symptomatology and quality of life were assessed using self‐report questionnaires. BMI, duration of illness and eating disorder diagnosis was obtained during a clinical interview.ResultsSeverity of the eating disorder and BMI were predictors of low quality of life. Duration of illness, contrary to clinical expectations was not a significant predictor of poor quality of life. In terms of differences across diagnostic groups, individuals with a diagnosis of anorexia nervosa in this sample were found to have lower psychological and physical/cognitive quality of life than those with an EDNOS or BN diagnoses. Copyright © 2009 John Wiley & Sons, Ltd and Eating Disorders Association.