Ovariectomy leads to progressive and significant increases in body weight gain and osteoporosis and is related to changes in serum and tissue cytokine profiles, such as observed in other models of overweight. We aimed to evaluate serum interleukin-1beta and interleukin-10 shortly after ovariectomy, before the establishment of overweight in rats. Female Wistar rats were submitted to ovariectomy, ovariectomy and estradiol replacement, or sham operation and compared with intact controls. Rats were killed 3, 6, 9, or 13 d after ovariectomy. Body mass and retroperitoneal fats were significant higher only 13 d after ovariectomy, and estradiol replacement to ovariectomized rats impaired both body mass and retroperitoneal fat gain. Shortly after ovariectomy (at 3 d) serum interleukin-1beta levels significantly increased in ovariectomized rats, treated or not with estradiol, while serum interleukin-10 levels increased only 9 d after ovariectomy. Our results suggest the existence of an important interplay between the immune system and ovarian function. This interplay occurs regardless of significant changes in adipose tissue compartment, as ovarian excision leads to short-term changes in the pattern of interleukin-1beta and interleukin-10 cytokine production that precede body weight gain and are not reverted by estradiol replacement.