Introduction: Sibutramine has been described as a drug recommended for treatment of obesity, since it has the ability to inhibit the reuptake of serotonin and noradrenaline in the central nervous system, thereby increasing energy expenditure. Objective: Investigate the anxiogenic and anxiolytic effects of acute and chronic treatment with sibutramine in rats submitted to the task of the elevated plus-maze. Methods: Diazepam was used as a positive control for the anxiolytic effect, and the task of the elevated plus-maze showed sensitivity to detect the effect. In the chronic treatment, sibutramine was ingested for a period of two months. Results: The acute and chronic treatments at the studied dose, which is described to produce a maximum effect of anti-obesity in rats, did not interfere with anxiety. Conclusions: The acute and chronic administration of sibutramine is not related to anxiolytic or anxiogenic effects. Arq Bras Endocrinol Metab. 2010;54(4):375-80