The aim of this study was to examine the changes in serum cytokine levels (Il-1alpha, Il-6, TNF-alpha) in ovariectomized rats with and without replacement estrogen therapy. Female Wistar rats were used. Rats were qualified for the following groups: Cl - control, SH - sham-operated, OV - after ovariectomy, OVH - after ovariectomy receiving 17beta-estradiol in three different doses (1.25, 12.5, 125 mug) during seven weeks. After ovariectomy the level of each examined cytokine was significantly increased. After the administration of three different doses of 17beta-estradiol the concentration of the examined cytokines was reduced in different degree.