Anorexia nervosa (AN) is a severe and often chronic disorder with uncertain aetiology and poor prognosis. New approaches to the understanding of the disorder are needed in order to aid the development of more effective treatments. Several authors have suggested that AN has a considerable overlap with obsessive-compulsive disorder (OCD) and that this may reflect common neurobiological, genetic, or psychological elements. However, more recent studies have suggested that AN may have a closer relationship with obsessive-compulsive personality traits such as those found in obsessive-compulsive personality disorder (OCPD). In this paper, evidence for links between the three conditions is reviewed, suggestions for further research are outlined and possible implications for the treatment of AN are presented.