Prompted by previous studies suggesting that bulimia nervosa in women may be associated with elevated serum levels of testosterone, we have evaluated the possible effect of androgen antagonism in this condition. To this end, women meeting the DSM-IV criteria of bulimia nervosa, purging type, were treated in a one-center study with the androgen receptor antagonist flutamide (n = 9), the serotonin reuptake inhibitor citalopram (n = 15), flutamide plus citalopram (n = 10), or placebo (n = 12) for 3 months using a double-blind design. Self-rated global assessment of symptom intensity suggests all active treatments to be superior to placebo. The reduction in binge eating compared with baseline was statistically significant in both groups given flutamide but not in the groups given citalopram only or placebo. A moderate and reversible increase in serum transaminase levels led to discontinuation in two subjects in the flutamide group. It is concluded that blockade of androgen receptors may reduce some of the symptoms of bulimia nervosa in women.