Context: Adrenal and extra-adrenal cortisol production may be involved in the development of metabolic syndrome (MetS). Objective: To investigate the activity of the hypothalamic-pituitary-adrenal (HPA) axis and the expression of HSD11B1, nuclear receptor subfamily 3, group C, member 1 (glucocorticoid receptors) a (NR3C1a) and b (NR3C1b) in the liver, subcutaneous adipose tissue (SAT) and visceral adipose tissue (VAT) of severely obese patients with and without MetS. Methods: The study included 37 severely obese patients (BMI R40 kg/m 2 ), 19 with MetS (MetSC group) and 18 without (MetSK group), studied before and during bariatric surgery. Before the day of surgery, urinary free cortisol (UFC) and diurnal variation of serum and salivary cortisol were estimated. During surgery, biopsies of the liver, VAT and SAT were obtained. The expression of HSD11B1, NR3C1a and NR3C1b was evaluated by RT-PCR.Results: UFC and area under the curve for 24-h profiles of serum and salivary cortisol were lower in the MetSK group. In the MetSK group, mRNA levels of HSD11B1 in liver exhibited a negative correlation with liver NR3C1a (LNR3C1a) and VAT expression of HSD11B1 was lower than the MetSC group. Conclusions: We observed a downregulation of the NR3C1a expression and lower VAT mRNA levels of HSD11B1 in the MetSK group, indicating a lower selective tissue cortisol production and action that could protect these patients from the metabolic consequences of obesity. In the MetSK group, a lower activity of the HPA axis was also detected. Taken together, cortisol in tissue and systematic level might play a role in the development of MetS in severely obese patients.