The concentration of unoccupied, occupied and total receptors for estradiol (E2R), unoccupied receptors for testosterone (TR) and progesterone (PsR) in the endometrium (E) and myometrium (M) of cycling gilts or sows after the second or the third farrow were measured. On day O (estrus) the concentration of E2R, TR and PsR reached the maximum for total uterus (M + E). On day 0, there were no differences between concentration of PsR, TR and occupied, unoccupied and total E2R for E and M. In other stages of estrous cycle, the concentration of receptors in E and M were considerably different both in cycling gilts or sows after second or third farrow. On day 13 (luteal phase), high levels of E2R were found but only for E, while there were the lowest level of occupied, unoccupied and total E2R for M. In sows, after the second or third farrow the concentration of E2R in E as well as in M at all stages of the estrous cycle was about three times higher than in cycling young gilts. The concentration of TR in E as well as in M was lowest on day 13, increased on day 17 and reached the highest level at estrous. The concentration of PsR in M was the lowest at luteal phase (day 13), increased on day 17 and reached the highest level at estrus. Significant negative correlation between the concentration of PsR and progesterone in the blood plasma was calculated for M, but not for E.