PURPOSE: The purpose of the study was to investigate psychological factors such as eating psychopathology, depression, and obsessive-compulsion that might influence self-harm behavior in patients with eating disorders. METHODS: Patients with eating disorders (n=135) who visited "M" clinic for eating disorders participated in the study. Data were collected from March to August 2007 using the Eating Disorder Inventory-2, Beck Depression Inventory, Maudsley Obsessional-Compulsive Inventory, and Self-Harm Inventory (SHI). RESULTS: The participants scored high on self-harm as well as on depression and obsessive-compulsion. On the SHI, a high frequency of self harm behavior such as 'torturing self with self-defeating thoughts', 'abused alcohol', 'hit self', and 'suicide attempt' were found for the participants. There were significant correlations between most eating psychopathology variables, depression, obsessive-compulsion, and self-harm behavior. 'Interoceptive awareness' (eating psychopathology), depression, and 'checking' (obsessive-compulsion) were significant predictors of self-harm behavior. CONCLUSION: Future interventions for patients with eating disorders should focus on assessing the possibility of self-harm and suicidal attempts, especially in those patients with high levels of eating psychopathology, depression, or obsessive-compulsion. Early intervention for depression and obsessive-compulsion could contribute to preventing self-harm and suicide in patients with eating disorders.