Abnormalities in central serotonin function have been implicated in the pathogenesis of anorexia nervosa. It is difficult, however, to separate neuroendocrine abnormalities induced by weight loss and malnutrition from those related primarily to the disorder itself. To minimize these influences, this study assessed long-term weight restored anorexics. A correlation between persistent eating-related psychopathology, co-morbid illness and serotonin dysfunction was sought. Nine female weight-restored out-patients who had previously fulfilled DSM-III-R criteria for anorexia nervosa and nine healthy controls participated. Following baseline estimation, prolactin and cortisol responses to 30 mg p.o. of D-fenfluramine were measured over a 5 h period. Eating related psychopathology was assessed using the Eating Disorders Inventory and Eating Attitudes Test. Depressive and obsessional symptoms were measured using the Beck Depressive and Maudsley Obsessive-Compulsive Inventories respectively. The Tridimensional Personality Questionnaire assessed impulsivity. The weight-restored anorexic group exhibited persistent eating-related psychopathology and significant co-morbid symptomatology. There was no difference between long-term weight-restored anorexics and controls in their endocrine response to D-fenfluramine. Long-term weight-recovered anorexic subjects continued to exhibit behavioural and attitudinal disturbances characteristic of anorexia nervosa. The results suggest that abnormalities in 5HT activity do not contribute significantly to trait status in anorexia nervosa.