Objectives: To investigate everyday memory and related processes in patients with eating disorders and to consider how problems with these processes may impact upon their psychosocial functioning and ability to engage in cognitively demanding aspects of treatment programmes. Design: Two cas e-control studies. Setting: Regional Eating Disorders Service in the North East of England. Participants: Patients with Anorexia Nervosa (AN), Bulimia Nervosa (BN) and Eating Disorder Not Otherwise Specified (EDNOS) [DSM-IV, 1994] attending an Eating Disorder Unit, and healthy volunteers. Main outcome measures: Self-report and objective measures of everyday memory and related processes; self-report and objective measures relating to state of illness; self-report measures of attendant anxiety and depression. Results: Patients were found to be impaired on all measures of memory and related processes. Degree of impairment correlated variously with state of illness measures and depression/anxiety measures. Conclusions: These data suggest that patients with eating disorders are impaired in their ability to engage in day-to-day and more directed activities that depend upon memory and related processes. Helping patients develop strategies to overcome these difficulties may be a useful nursing addition to existing treatment packages and may improve treatment efficacy.