Background: It is well known that selective serotonin reuptake inhibitors (SSRIs) can cause sexual dysfunction, so it is possible that sibutramine, a serotonin and norepinephrine reuptake inhibitor, could induce sexual dysfunction. Design and subjects: The effect of sibutramine on sexual function was evaluated in 46 overweight and obese (body mass index (BMI) X23 kg/m 2 ) but otherwise healthy married women (28-44 years). Participants were randomly assigned at baseline to either the sibutramine or control group. The Female Sexual Function Index (FSFI) questionnaire was used to assess sexual function at baseline and after treatment with behavioral therapy plus sibutramine 10 mg once daily or behavioral therapy alone (control) for 8 weeks.Results: Mean weight loss from baseline to week 8 was À6.03% in sibutramine group and À0.38% in the control group. There was significant improvement of FSFI total score, arousal domain score and lubrication domain score in the sibutramine group (Po0.05), and significant differences in arousal, orgasm, satisfaction domain score and total score (Po0.05) in favor of sibutramine. Decreases in body weight and BMI were correlated with the improvement of arousal (r ¼ À0.44 and r ¼ À0.48, respectively) and orgasm (r ¼ À0.45 and r ¼ À0.46, respectively) domains. Conclusion: Treatment with sibutramine plus behavioral therapy did not induce sexual dysfunction and sibutramine-induced weight reduction appeared to have a positive impact on sexual function in this small group of overweight and moderately obese women. The degree of improvement in sexual function was correlated with the degree of weight reduction.