It has been known that estradiol modulates food intake and body weight gain. However, the mechanisms of estradiol-induced hypophagia and the effects of estradiol on energy expenditure are not fully established. Therefore, the present study evaluated the effect of ovariectomy with and without estradiol replacement on food intake and body weight and hypothalamic gene expression for proopiomelanocortin (POMC), agouti-related protein (AgRP), neuropeptide Y (NPY) in the arcuate nucleus (ARC) and long form of the leptin receptor (ObRb), melaconocortin receptor 4 (MC4-R), corticotrophin releasing factor (CRF) and cocaine- and amphetamine-regulated transcript (CART) in the paraventricular nucleus (PVN). Female Wistar rats, anesthetized with 2.5% 2.2.2- tribromoethanol (1 mL/100 g body weight, ip), were subjected to bilateral ovariectomy and divided into two groups: OVX (corn oil: 0.1 mL/rat, sc) and OVX+E (estradiol cypionate: 10 µg/Kg body weight, sc). After 8 days, rats were decapitated at 5pm (before food intake) or 10 pm (after food intake for 4 hours) for blood and brain collection. Plasma leptin levels were determined by radioimmunoassay and mRNA expression was obtained by real time PCR, from total RNA isolated from micropunched ARC and PVN. Results were analyzed using unpaired t-test or two way ANOVA, followed by Student-Newman-Keuls post-hoc test. Data are shown as means±SEM. We observed that estradiol replacement in OVX rats induced lower food intake and body weight gain, lower leptin plasma levels both before and after feeding. A significant reduction of AgRP and NPY mRNA expression was observed in estradiol-treated animals at 5 pm, however, there was no difference in POMC mRNA expression in the ARC at 5 pm and 10 pm in both OVX and OVX+E groups. ObRb, MC4-R, CRF and CART mRNA expression in the PVN were significantly higher in OVX+E, compared to OVX group at 5 pm, with no differences between groups at 10 pm. In conclusion, estradiol affects energy homeostasis through its effects on food intake, which are mediated by peripheral factors, such as leptin, released by white adipose tissue, and differential expression of hypothalamic neuropeptides.