Eating disorder patients evidenced very often a low self-esteem. Self-esteem in eating disorder patients is excessively based on body dissatisfaction. In eating disorders there seems to be a link between body image dissatisfaction and social anxiety. We hypothesised: self-esteem would be as low in eating disorder patients as in social phobia patients; self-esteem would be lower in eating disorder patients with social phobia than in patients with social phobia alone; self-esteem would be lower in eating disorder patients with depressive cognitions than in social phobia patients with depressive cognitions; self-esteem could have different characteristics in the two disorders; self-esteem would be as low in anorexia as in bulimia; 103 eating disorder patients (33 restrictive anorectics, 34 anorectics-bulimics, 36 bulimics) and 26 social phobia patients diagnosed according to DSM IV and ICD-10 criteria have been investigated by the Self-Esteem Inventory of Coopersmith, the Assertiveness Schedule of Rathus, the Fear Survey Schedule of Wolpe (FSS III) and the Beck Depression Inventory (BDI). Patients were free of medication and presented no episode of major depression according to DSM IV criteria. Evaluations took place before any psychotherapy. Self-esteem in eating disorder patients is reduced at the same level as in social phobia patients; 86.1% of the total sample and 84.5% of the eating disorder patients have a very low self-esteem (score 33 in the SEI). Eating disorder patients have significantly higher scores in the Social (p=0.016) and Professional (p=0.0225) sub-scales of the SEI than social phobia patients. Eating disorder patients show higher scores on the Assertiveness Schedule of Rathus (p=0.0013) than social phobia patients. Eating disorder patients disclose higher scores on the BDI (p=0.0003) but eating disorder patients with depressive cognitions do not differ from social phobia patients with depressive cognitions in the level of self-esteem. The FSS III scores are significantly lower in eating disorder patients (p<0.0001). There is a difference in the nature of the deficit of self-esteem between the two patient populations. Self-esteem is not influenced by the Body Mass Index (BMI) and is identically reduced in all groups of eating disorder patients. Whereas eating disorder patients have the same complaints compared to social phobia, they differ significantly from social phobia patients in their characteristics of social phobia and self-esteem.